Clinical Genetics 1975: 7 : 134-143
A
new case of the trisomy 9p syndrome
Report of a patient w i t h unusual chromosome findings (46,XX/47,XX, i (9p)) and a peculiar congenital heart defect
+
E. ORYE,H. VERHAAREN, H. VANEGMOND, AND A. DEVLOO-BLANCQUAERT Laboratory of Cytogenetics, Department of Pediatrics, Rijksuniversiteit Ghent, Belgium A girl is described for whom an unusual chromosome constitution was found and who had a peculiar congenital heart defect. The girl showed the main clinical features of the trisomy 9p syndrome, such as psychomotor retardation, microcephaly and brachycephaly, enophthalmos, antimongoloid eye slant, hypertelorism, abnormal ears, a globulous nose, downward slanting mouth, hypoplasia of phalanges and abnormal palmar creases. In addition, the girl had an incomplete harelip, a cleft palate and a peculiar congenital heart defect, a ventricular septa1 defect with pulmonary valve stenosis and a marked hypoplasia of the pulmonary trunk, including the bifurcation. Chromosome analysis revealed a mosaicism with normal and abnormal mitoses (47 chromosomes). The extra chromosome was a metacentric E16-like chromosome, which on the basis of the G, R, Q and Giemsa-11-banding could be identified as an isochromosome of the short arm of chromosome 9 (46,XXM7,XX,+ i (9) (pter-tcen-pter)). The patient consequently had a partial tetrasomy of the short arm of chromosome 9. Received 8 July, accepted for publication 16 September 1974
A new malformation syndrome, resulting from a chromosomal imbalance, was recognized in 1970 by RethorC and coworkers. These authors described four patients with a trisomy for the short arm of chromosome 9 and referred to five similar patients in previously published reports (Edwards et al. 1962, Lejeune et al. 1966, Lord et al. 1967). Since 1970, eight more patients have been described (Cantu et al. 1971, Hoehn et al. 1971, Rott et al. 1971, Newton et al. 1972, Baccichetti & Tenconi 1973, Ghymers et al. 1973, RethorC et al. 1973). In most of these patients, the trisomy 9p was the result of a translocation. In the
girl reported here, a more peculiar aberration was found, an isomchromosome of the short arm of chromosome 9. Furthermore, a peculiar congenital heart defect was present in our patient. Case Report
The patient, born 27 May 1972, was the first child of nonconsanguineous parents. Both the father and mother were 25 years old at the time of her birth. The mother, with the exception of a pyelitis and viral hepatitis in her youth, is healthy and so is the father. The pregnancy was unremarkable except for a bronchitis in the 4th
A NEW CASE OF THE TRISOMY 9p SYNDROME
month, which was treated with tetracyclines, rondomycine and dextrometorphan. There was no history of irradiation and smoking was limited to two cigarettes a day. The delivery was spontaneous and at term. The girl weighed 2290 g, her length was 46.5 cm and her head circumference 30.5 cm. Because of the facial dysmorphy, cleft palate, harelip and a slight cyanosis of the extremities, the infant was transferred soon after birth to the pediatric department of the academic hospital of Ghent. Physical examination (Fig. 1) Multiple congenital anomalies were noted. The face has a somewhat angular shape and the forehead is narrow. There is also a moderate microcephaly. The hairs are very thin, scanty and of poor quality. The
135
fontanels and the sutures, especially the coronal sutures, are wide open. The eyes are deep set and there is an intermittent convergent strabismus. The interpupillary distance at the age of 1 % years is 6.6 crn, the normal range being 3.8-5.6 cm (Pryor 1969). This means a distinct hypertelorism. Slight epicanthal folds and anti-mongoloid eye slants are also present. The eyebrows are scanty, especially in the medial third, where they join the supranasal downy hairs. The eyelashes of the upper eyelids are very long and bent upwards; those of the lower eyelids are scarce in the lateral two thirds and lacking in the medial third. The ears are small, low-set, and have small auditory canals. The helix leans against the skull. There is a clear angula-
Flg. I . The patient at the age of 16 months. (A) frontal view and (B) lateral view.
136
ORYE ETAL.
Fig. 2. Cine-angiocardiography. (A) Lateral projection of injection in the right ventricle. Slight infundibular stenosis and marked hypoplasia of pulmonary trunk and bifurcation. (6) Frontal projection of injection in the right ventricle. The pulmonary artery main branches further on are greatly dilated and decrease to very small vessels in the periphery of both lungs. (Photographs kindly provided by Prof. Dr. M. Kunnen, Department of Radiology.)
tion between the horizontal and vertical part of the anti-helix of both ears and of the helix of the right ear. The upper part of the anti-helix is undivided. The bridge of the nose is broad and depressed and the nose pyramid is very globulous and asymmetrical. The top of the nose is turned upwards, while the body of the nose is bent to the left as a consequence of an incomplete harelip on the right side. There is a cleft of the weak and bony palate. The lips are very thin and the inner side of the upper lip is fused with the gingival wall of the upper jaw. The edges of the mouth are bent downwards. The neck is short and thick and shows an excessive folding of the dorsal skin. The chest is large and barrel-like; slightly wideset nipples are present. The pelvis is very narrow and the extremities are small compared to the barrel-like chest. There are slight cubita valga. The hands and feet are small and there is a clinodactyly of the fifth fingers, an absent interphalangeal crease of the left fifth finger and a simian
line in the right hand. Normal female genitalia are present. Clinical course and cardiovascular findings I n spite of the harelip and cleft palate, there were no feeding difficulties. A few days after birth the girl developed a systolic murmur 3/6 with a maximum at the 2nd and 3rd left interspace, suggesting a stenosis of the pulmonary valve. Roentgenographic examination of the heart and an electrocardiogram were normal at that time. At the age of 6 months, however, the diagnosis of pulmonary valve stenosis was confirmed on electrocardiogram by a right axis deviation and a progressively more pronounced hypertrophy of the right ventricle and even of the right atrium. A roentgenographic examination of the thorax showed a moderately enlarged heart with hypertrophy of the right ventricle. The vascular markings were diminished in the lung periphery but seemed increased in the hilar region. The clinical course was normal without cardiological problems, even during correc-
137
A N E W CASE O F T H E T R I S O M Y 9 p S Y N D R O M E
tion of the harelip at the age of 10 months. At the age of 14 months, however, a paralysis of the facial nerve (paralysis of the central type) was noted and several anoxemic attacks appeared. Therapy with digitalis was without result, but a treatment with (%blocking agents (propranolol) was very effective. At the age of 16 months, a heart catheterization was performed. Pressures and oxygen saturation were normal in the left heart. In the right ventricle, pressure was markedly increased (100 mmHg) and a rise in the oxygen saturation was noted between the right atrium and ventricle. It was impossible to attain the pul-
monary artery. The angiogram revealed a large defect of the interventricular septum, situated in the membranous part. The right ventricle showed a slight hypertrophy of the infundibulum with stenosis of the pulmonary valve. A pronounced hypoplasia of the pulmonary artery trunk, including the bifurcation (Fig. 2A) was seen. A marked poststenotic dilatation of both pulmonary main branches was noted and these arteries decreased very quickly to very small vessels in the periphery of both lungs (Fig. 2B). During the subsequent readmissions, the psychomotor retardation of the girl continued to become more obvious. At the age
Table 1
Dermatoglyphic analysis of the proband and her parents Finger pattern
v
Proband Father Mother
IV
Right hand 111 IV
v
T.FRC.
u
w
w
w
w
w
w
w
u
w
1118
10/10
12/10
12/12
8/13
14/15
810
u
13/11
w
u
2010
18/11
1210
15/16
23/13
26/20
11/15
1510
2012
1410
U
U
U
R
U
U
R
U
U
U
22/0
11/0
4/0
0/14
1110
ll/O
0118
5/0
18/0
la0
R
Mother
II
1010
Proband
L R L R
I
I
u
Palm formula
Father
II
810
Palm pattern
L
Left hand 111
., ,
. . .
.
7-9 11 7 7 9 11
,
. .
. ,
u
9 11
5" 5" 9 9
w
. .
. . . .
5" 9 5' . 5' , 5" . 7
.
. .
w
3 -t 3 -t 3 - t 3 - t 3 -t 4 -t
w
+13 e l 3+13+13+13 +13 -
w
A" . A" . A" . A " . A" . A" .
u
Le
0 0
0 V/L' V/Lr
. . . . . .
0 0
0 0 0 0
.L
.
L
112 179 126 atdangle
abcount
46"
36 31 44 43 41 43
.L
52'
.
42' 43" 44" 43"
. 0 .O . L .O . L L . 0 .L . 0
Proband : hallucal area : L : large distal loop R : large whorl
Table 2
Chromosome counts in the proband Chromosome Number Leukocytes Fibroblasts'
+
45
45( ?16)
2
6
46
46(+?16)
47( ?16)
+
Total
4
19 5
69 37
100 59
17
(+?16) mitoses in which the abnormal Ela-like chromosome was present * cells were taken from a first subculture. Total culture age was 20 d
138
ORYE ET AL
Fig. 3. Complete karyotype of the propositus (left) and partial karyotypes (right) of the group E chromosomes and the metacentric extra chromosome (the abnormal chromosome is underlined).
of 15 months, the child was able to roll from supine to the prone position, but still was not able to stand upright, nor hold her head upright without support. Investigations and Results
Analytical findings Peripheral blood analysis, serology and urine examinations were normal. Metabolic screenings (aminoacids) in blood and urine were negative. An electromyography of the facial musculature, an electroencephalography, a brain scan, a subdural puncture and the ophthalmological examination at the age of 14 months because of the facial nerve paralysis, were all normal. X-rays of the skull at the age of 16 months revealed still wide open fontanels and sutures. The interorbital distance was 25 mm (normal values: 18.5 mm k 1.9 mm). X-rays of the hands showed a slight shortening of the medial phalanges of the fifth fingers.
The dermal ridge system Apart from the abnormal creases already mentioned, no peculiar features are to be noted concerning the dermal ridge system of the patient (Table 1). On the fingers, there are seven whorls and three ulnar loops. The axial triradius in both hands is at the normal position and terminates at 13. No absent digital triradii b and c are seen. Chromosome analysis Venous blood for chromosome studies was obtained from the proband on 20 May 1972. One hundred mitoses were counted and analyzed (Table 2) and a modal chromosome number of 47 was found. The extra chromosome was an abnormal E16like chromosome, which had the size of a normal E l 6 chromosome but a more metacentric centromere position (Fig. 3). Both arms of the abnormal chromosome seemed equal in length. In only six mitoses (four
A NEW CASE OF THE TRISOMY 9p SYNDROME
with 46,XX) was the E16-like chromosome not seen. Since 25 mitoses were found which showed the E16-like chromosome and a random loss of one or two of the other chromosomes, these six mitoses must be considered most likely to be artifacts and not a second and normal cell line. A skin biopsy was obtained on 4 October 1973, and fibroblast cultures were established. Fifty nine mitoses were analyzed (Table 2), of which 42 had the abnormal chromosome. Of these 42 mitoses, five had 46 chromosomes and showed an artifactual loss of another chromosome. However, in 17 (28.8 %) mitoses a normal 46,XX chromosome constitution was seen. Apparently, in the skin fibroblasts, a mosaic 46,XX/47,XX,+? 16 is present. Both parents had normal chromosomes. In order to identify the extra E16-like chromosome, an analysis of the G-banding pattern was performed on leukocyte chromosome preparations according to the method of Shiraishi Lk Yosida (1972) and Seabright (1972). Analysis of the R-banding (Carpentier et al. 1972), the Giemsa-llbanding (Bobrow et al. 1972) and the Qbanding (Caspersson et al. 1970) was carried out with the same material. Both arms
139
of the abnormal chromosome show a similar G - and R-banding pattern (Fig. 4). Moreover, this pattern is comparable to the banding pattern of the short arm of chromosome 9. The abnormal chromosome is most probably an isochromosome of the short arm of chromosome 9. The patient’s chromosome constitution is most probably: 46,XX/47,XX,+i(9) (pter + cen + pter). These findings were confirmed by the Qbanding and Giemsa-11-banding studies. In this last technique, the abnormal chromosome showed a strongly stained centromeric region (Fig. 4D). With this technique, the centromeric region is stained only in chromosomes 7 and 10 and especially chromosomes 9. However, the G- and R-banding patterns of the short arm of chromosomes 7 and 10 are completely different from the banding patterns of both arms of the abnormal chromosome. Length measurements of the abnormal chromosome and of the short arm of the normal chromosome 9 were carried out on photographic prints of G-banded mitoses (final enlargement X 3300), using a Zeiss Micro-Videomat, the qualitative and quantitative analyzer of the televised image. The short arm length of the normal chromo-
Fig. 4. The normal and abnormal chromosome 9: (A) in G-banded mitoses according to the technique of Shiraishi 8. Yosida (1972) and ( 8 ) of Seabright (1972): (C) in R-banded mitoses according to the technique of Carpentier et al. (1973): and (D) in Giemsa-11-banded mitoses according to the technique of Bobrow et al. (1972).
140
ORYE ETAL
m
R- BANDING
/J
24-2 21
\
c
13
i
G -BANDING
-9
fv C
21
13
y
i
12
11
13 12
12 f3
ZI
Fig. 5. Reflectodensitometer tracings of the G-banded and R-banded normal and abnormal chromosome 9.
The points of maximal and minimal density of the dark and light bands, respectively, of the short arms are indicated.
some 9 was 5.01 5 0.71 mm. The centromere index of the abnormal chromosome was 49.47 & 0.02 and the total length was 10.18 ? 1.60 mm. The mean arm length was 5.09 ? 0.80 mm. Measurements were also carried out on reflectodensitometer tracings of the normal and abnormal chromosome 9 in G-banded as well as in R-banded
mitoses. These tracings were obtained by using the “Klini-Siekel KSII” scanning reflectodensitometer (developed by J. B. Bijlsma and H. F. France of the Laboratory of Anthropobiology and Human Genetics, Amsterdam). On these tracings, the points of maximal and minimal density of the dark and light bands, respectively, were
Table 3 Mean and standard deviation of the length measurements of the distances between the endpoint of the short arm and the points, corresponding with the maximal and minimal density of the dark and light bands Fespectively, on reflectodensitometer tracings of the short arm of the normal and both arms of the abnormal chromosome 9 in R- and Gbanded mitoses (values expressed as a percentage of total short arm length) R-bands
p 24-2
P 21
P 13
G-bands
P 21
P 13
P 12
i (9 P) (n = 35)
30.1 C 5.2 33.7 f 6.7
48.6 f5.7 50.5 6.4
65.9 f 6.4 67.7 f 6.6
i (9 p) (n = 42)
36.8 f 5.9 39.5 C 6.8
67.9 f 5.8 69.0 C 6.3
81.3 f 7.7 82.6 C 8.9
30.2 C 5.5
48.1 k 7.3
66.4 & 6.7
f 7.9
66.9 f 10.6
79.4 If. 8.2
9 N
(n = 34)
*
9 N
= 39)
36.1
A NEW CASE OF THE TRISOMY 9p SYNDROME
located on the abscissa, as indicated in Fig. 5. The distances between the end point of the short arm and the points corresponding to the light and dark bands were measured and expressed as a percentage of the total short arm length. The values obtained for the light and dark G-bands p13, p12 and p21, and the dark and light Rbands p13, p21 and p24-2 of the short arm of the normal and both arms of the abnormal chromosome 9 are fully comparable (Table 3). These measurements thus give additional evidence for the isochromosome nature of the abnormal chromosome.
Discussion According to Rethor6 et al. (1973), a characteristic clinical entity corresponds to the trisomy of the short arm of chromosome 9. The main clinical features are severe psychomotor retardation, moderate microcephaly, brachycephaly, enophthalmos, antimongoloid slant of the palpebral fissures, mild hypertelorism, protruding ears with abnormal antihelix, a globulous nose, downward slanting mouth and hypoplasia of the phalanges. Some peculiarities of the dermal ridge system are also noted: transverse palmar flexion creases and the absence of a digital triradius or the fusion of triradii b and c. In most of the published cases of this syndrome, a partial or complete trisomy 9p was present, resulting from a balanced chromosome rearrangement in one of. the parents. In our patient, unusual clinical features and a peculiar chromosome aberration were seen. Although the above mentioned clinical features, typical of the trisomy 9p syndrome, were present, our patient seemed to be more severely affected than previously reported cases. Indeed, in addition, our patient exhibited an incomplete harelip on the right side, a cleft of the weak and bony palate, and a peculiar congenital heart de-
141
fect. This is most probably related to the exceptional chromosome findings. Instead of a trisomy 9p, a tetrasomy with mosaicism was found. As far as we know, an isochromosome 9p has not yet been identified. Only one other case has been published in which a tetrasomy with mosaicism was found (Ghymers et al. 1973). Although, as the authors themselves mentioned, the clinical data are incomplete, a congenital heart defect is probably present in this case as well. However, no cleft palate was noted. Since only a limited number of patients with a trisomy 9p is known at present, it may probably be too soon t o conclude that patients with a tetrasomy 9p represent a distinct subtype of the trisomy 9p syndrome, characterized by some more severe congenital anomalies in addition to these of the trisomy 9p syndrome. The chromosome findings in our patient are, in several aspects, comparable to those of the patient of Ghymers et al. (1973). The abnormal chromosome in our case is an isochromosome of the short arm with only a small Giemsa-11 positive centromere region. In the case of Ghymers et al. (1973), the abnormal chromosome most probably resulted from a more complex rearrangement. It consisted of two short arms of chromosome 9 with intercalary, an enlarged Giemsa-11 positive region, which is larger than the corresponding region in the normal chromosome 9. Apart from the centromere position, which is median in our case and submedian in Ghymers’ case, the abnormal chromosomes can be described as (9p,h-, 9p) and (9p,h+, 9p), respectively. Since quantitative changes of the Giemsa-11 positive region in chromosome 9 seem to be compatible with normal development (Abrisqueta et al. 1973), the effective chromosome imbalance in both patients is most probably similar. Another aspect is the mosaicism. In both cases, only abnormal cells were found in the peripheral
142
ORYE ETAL
blood preparations, while in a skin biopsy culture, only normal mitoses were seen in Ghymers' case, a n d normal a n d abnormal mitoses in our case. T h e congenital heart defect with hypoplasia of the pulmonary artery trunk and the origin of both main pulmonary branches is a n unusual cardiological finding. To our knowledge, these supravalvular stenoses have not previously been described in chromosomal syndromes. They a r e found in some rare cases of intrauterine damage t o the fetus (Blancquaert e t al. 1966, Wasserman e t al. 1968, Keutel e t al. 1972, Watson & Miller 1973).
References
Abrisqueta, J. A., I. Cortejarena, A. PerezBousono & M. Perez-Sotelo (1973). Transmission d'un chromosome marqueur (9 q h) dam trois gCnCrations. A n n . Gknkt. 16, 203206. Baccichetti, C. & R. Tenconi (1973). A new case of the trisomy for the short arm of nr 9 chromosome. J . med. Genet. 10, 296-299. Blancquaert, A., C. Dupuis, C. Hooft, J. P. Nuyts & R. Pannier (1966). StCnoses pulmonaires et aortiques postvalvulaires avec facies particulier et retard intellectuel. Acta cardiol. (Brux.) 21, 61 1-643. Bobrow, M., K. Madan & P. L. Pearson (1972). Staining of some specific regions of human chromosomes, particularly the secondary constriction of N o9. Nature N e w Biol. 238, 122-124. Cantu, J. M., L. Buentello & S. Armendares (1971). Trisomie Cp : un nouveau syndrome. Ann. Ge'ne't. 14, 177-186. Carpentier, S., B. Dutrillaux & J. Lejeune (1972). Effet du milieu ionique sur la dCnaturation thermique mCnagCe des chromosomes humains. Ann. Ge'nkt. 15, 203-205. Caspersson, T., L. Zech, C. Johansson & E. J . Modest (1970). Identification of human chromosomes by DNA-binding fluorescent agents. Chromosoma (Bert.) 30, 215-227. Edwards, J . H., M. Fraccaro, P. Davies & R. B. Young (1962). Structural heterozygosis in man: analysis of two families. Ann. hum. Genet. 26, 163-178.
Ghymers, D., B. Hermann, C. Disteche & J. Frederic (1973). T6trasomie partielle du chromosome 9, i I'ttat de mosaique, chez u n enfant porteur de malformations multiples. H u m . Genet. 20, 273-282. Hoehn, H., W. Engel & H. Reinwein (1971). Presumed trisomy for the short arm of chromosome N o 9 not due to inherited translocation. Hum. Genet. 12, 175-181. Keutel, J., G. Jorgensen & P. Gabriel (1972). A new autosomal recessive syndrome: peripheral pulmonary stenoses, brachytelephalangism, neural hearing loss and abnormal cartilage calcificationdossification. Birth Defects: Original Article Series VIII, 60-68. Lejeune, J., R. Berger, M. 0. RethorC, Ch. Salmon & M. Kaplan (1966). Translocation Cc/F familiale, dkterminant une trisomie pour le bras court du chromosome 12. Ann. Gkne't. 11, 88-94. Lord, P. M., M. D. Casey & B. M. Laurence (1967). A new translocation between chromosomes in the 6-12 and 21-22 groups. J . med. Genet. 4, 169-176. Newton, M. S., C. Cunningham, P. A. Jacobs, W. H. Price & I. A. Fraser (1972). Chromosome survey of a hospital for the mentally subnormal. Part 2: Autosome abnormalities. Clin. Genet. 3, 226-248. Pryor, H. B. (1969). Objective measurement of interpupillary distance. Pediatrics 44, 973977. RethorC, M. O., H. Hoehn, H. D. Rott, J. Couturier, B. Dutrillaux & J. Lejeune (1973). Analyse de la trisomie 9 p par dknaturation mCnag6e. A propos d'un nouveau cas. H u m . Genet. 18, 129-138. RethorC, M. O., L. Larget-Piet, D. Abonyi, M. Boeswillwald, R. Berger, S. Carpentier, J. Cruveiller, B. Dutrillaux, J. Lafourcade, M. Penneau & J. Lejeune (1970). Sur quatre cas de trisomie pour le bras court du chromosome 9. Individualisation d'une nouvelle entiti morbide. Ann. Ge'ne't. 13, 217-232. Rott, H. D., G. Schwanitz K. P. Grosse (1971). Partielle Trisomie Cq bei balancierter B,/Cq- Translokation bei der Mutter. Z . Kinderheilk. 109, 293-299. Seabright, M. (1972). The use of proteolytic enzymes for the mapping of structural rearrangements in the chromosomes of man. Chrornosoma (Bert.) 36, 204-210. Shiraishi, Y. & T. H. Yosida (1972). Banding pattern analysis of human chromosomes by use of a urea treatment technique. Chromosoma (Berl.) 37, 75-83. (&
A NEW CASE OF THE TRISOMY 9p SYNDROME
Wasserman, M. P., P. J. Varghese & R. D. Rowe (1968). The evolution of pulmonary arterial stenosis associated with congenital rubella. Amer. Heart J . 76, 638444. Watson, G. H. & V. Miller (1973). Arteriohepatic dysplasia. Familial pulmonary artery stenosis with neonatal liver disease. Arch. Dis. Childh. 48. 459-466.
Address: Dr. Sc. Edward Orye Laboratory o f Cytogenetics Department o f Pediatrics (Dir.: Prof. Dr. C . H o o f t ) Rijksuniversiteit Gent D e Pintelaan 135 B - 9000 Ghent Belgium
143
A
new case of the trisomy 9p syndrome
Report of a patient w i t h unusual chromosome findings (46,XX/47,XX, i (9p)) and a peculiar congenital heart defect
+
E. ORYE,H. VERHAAREN, H. VANEGMOND, AND A. DEVLOO-BLANCQUAERT Laboratory of Cytogenetics, Department of Pediatrics, Rijksuniversiteit Ghent, Belgium A girl is described for whom an unusual chromosome constitution was found and who had a peculiar congenital heart defect. The girl showed the main clinical features of the trisomy 9p syndrome, such as psychomotor retardation, microcephaly and brachycephaly, enophthalmos, antimongoloid eye slant, hypertelorism, abnormal ears, a globulous nose, downward slanting mouth, hypoplasia of phalanges and abnormal palmar creases. In addition, the girl had an incomplete harelip, a cleft palate and a peculiar congenital heart defect, a ventricular septa1 defect with pulmonary valve stenosis and a marked hypoplasia of the pulmonary trunk, including the bifurcation. Chromosome analysis revealed a mosaicism with normal and abnormal mitoses (47 chromosomes). The extra chromosome was a metacentric E16-like chromosome, which on the basis of the G, R, Q and Giemsa-11-banding could be identified as an isochromosome of the short arm of chromosome 9 (46,XXM7,XX,+ i (9) (pter-tcen-pter)). The patient consequently had a partial tetrasomy of the short arm of chromosome 9. Received 8 July, accepted for publication 16 September 1974
A new malformation syndrome, resulting from a chromosomal imbalance, was recognized in 1970 by RethorC and coworkers. These authors described four patients with a trisomy for the short arm of chromosome 9 and referred to five similar patients in previously published reports (Edwards et al. 1962, Lejeune et al. 1966, Lord et al. 1967). Since 1970, eight more patients have been described (Cantu et al. 1971, Hoehn et al. 1971, Rott et al. 1971, Newton et al. 1972, Baccichetti & Tenconi 1973, Ghymers et al. 1973, RethorC et al. 1973). In most of these patients, the trisomy 9p was the result of a translocation. In the
girl reported here, a more peculiar aberration was found, an isomchromosome of the short arm of chromosome 9. Furthermore, a peculiar congenital heart defect was present in our patient. Case Report
The patient, born 27 May 1972, was the first child of nonconsanguineous parents. Both the father and mother were 25 years old at the time of her birth. The mother, with the exception of a pyelitis and viral hepatitis in her youth, is healthy and so is the father. The pregnancy was unremarkable except for a bronchitis in the 4th
A NEW CASE OF THE TRISOMY 9p SYNDROME
month, which was treated with tetracyclines, rondomycine and dextrometorphan. There was no history of irradiation and smoking was limited to two cigarettes a day. The delivery was spontaneous and at term. The girl weighed 2290 g, her length was 46.5 cm and her head circumference 30.5 cm. Because of the facial dysmorphy, cleft palate, harelip and a slight cyanosis of the extremities, the infant was transferred soon after birth to the pediatric department of the academic hospital of Ghent. Physical examination (Fig. 1) Multiple congenital anomalies were noted. The face has a somewhat angular shape and the forehead is narrow. There is also a moderate microcephaly. The hairs are very thin, scanty and of poor quality. The
135
fontanels and the sutures, especially the coronal sutures, are wide open. The eyes are deep set and there is an intermittent convergent strabismus. The interpupillary distance at the age of 1 % years is 6.6 crn, the normal range being 3.8-5.6 cm (Pryor 1969). This means a distinct hypertelorism. Slight epicanthal folds and anti-mongoloid eye slants are also present. The eyebrows are scanty, especially in the medial third, where they join the supranasal downy hairs. The eyelashes of the upper eyelids are very long and bent upwards; those of the lower eyelids are scarce in the lateral two thirds and lacking in the medial third. The ears are small, low-set, and have small auditory canals. The helix leans against the skull. There is a clear angula-
Flg. I . The patient at the age of 16 months. (A) frontal view and (B) lateral view.
136
ORYE ETAL.
Fig. 2. Cine-angiocardiography. (A) Lateral projection of injection in the right ventricle. Slight infundibular stenosis and marked hypoplasia of pulmonary trunk and bifurcation. (6) Frontal projection of injection in the right ventricle. The pulmonary artery main branches further on are greatly dilated and decrease to very small vessels in the periphery of both lungs. (Photographs kindly provided by Prof. Dr. M. Kunnen, Department of Radiology.)
tion between the horizontal and vertical part of the anti-helix of both ears and of the helix of the right ear. The upper part of the anti-helix is undivided. The bridge of the nose is broad and depressed and the nose pyramid is very globulous and asymmetrical. The top of the nose is turned upwards, while the body of the nose is bent to the left as a consequence of an incomplete harelip on the right side. There is a cleft of the weak and bony palate. The lips are very thin and the inner side of the upper lip is fused with the gingival wall of the upper jaw. The edges of the mouth are bent downwards. The neck is short and thick and shows an excessive folding of the dorsal skin. The chest is large and barrel-like; slightly wideset nipples are present. The pelvis is very narrow and the extremities are small compared to the barrel-like chest. There are slight cubita valga. The hands and feet are small and there is a clinodactyly of the fifth fingers, an absent interphalangeal crease of the left fifth finger and a simian
line in the right hand. Normal female genitalia are present. Clinical course and cardiovascular findings I n spite of the harelip and cleft palate, there were no feeding difficulties. A few days after birth the girl developed a systolic murmur 3/6 with a maximum at the 2nd and 3rd left interspace, suggesting a stenosis of the pulmonary valve. Roentgenographic examination of the heart and an electrocardiogram were normal at that time. At the age of 6 months, however, the diagnosis of pulmonary valve stenosis was confirmed on electrocardiogram by a right axis deviation and a progressively more pronounced hypertrophy of the right ventricle and even of the right atrium. A roentgenographic examination of the thorax showed a moderately enlarged heart with hypertrophy of the right ventricle. The vascular markings were diminished in the lung periphery but seemed increased in the hilar region. The clinical course was normal without cardiological problems, even during correc-
137
A N E W CASE O F T H E T R I S O M Y 9 p S Y N D R O M E
tion of the harelip at the age of 10 months. At the age of 14 months, however, a paralysis of the facial nerve (paralysis of the central type) was noted and several anoxemic attacks appeared. Therapy with digitalis was without result, but a treatment with (%blocking agents (propranolol) was very effective. At the age of 16 months, a heart catheterization was performed. Pressures and oxygen saturation were normal in the left heart. In the right ventricle, pressure was markedly increased (100 mmHg) and a rise in the oxygen saturation was noted between the right atrium and ventricle. It was impossible to attain the pul-
monary artery. The angiogram revealed a large defect of the interventricular septum, situated in the membranous part. The right ventricle showed a slight hypertrophy of the infundibulum with stenosis of the pulmonary valve. A pronounced hypoplasia of the pulmonary artery trunk, including the bifurcation (Fig. 2A) was seen. A marked poststenotic dilatation of both pulmonary main branches was noted and these arteries decreased very quickly to very small vessels in the periphery of both lungs (Fig. 2B). During the subsequent readmissions, the psychomotor retardation of the girl continued to become more obvious. At the age
Table 1
Dermatoglyphic analysis of the proband and her parents Finger pattern
v
Proband Father Mother
IV
Right hand 111 IV
v
T.FRC.
u
w
w
w
w
w
w
w
u
w
1118
10/10
12/10
12/12
8/13
14/15
810
u
13/11
w
u
2010
18/11
1210
15/16
23/13
26/20
11/15
1510
2012
1410
U
U
U
R
U
U
R
U
U
U
22/0
11/0
4/0
0/14
1110
ll/O
0118
5/0
18/0
la0
R
Mother
II
1010
Proband
L R L R
I
I
u
Palm formula
Father
II
810
Palm pattern
L
Left hand 111
., ,
. . .
.
7-9 11 7 7 9 11
,
. .
. ,
u
9 11
5" 5" 9 9
w
. .
. . . .
5" 9 5' . 5' , 5" . 7
.
. .
w
3 -t 3 -t 3 - t 3 - t 3 -t 4 -t
w
+13 e l 3+13+13+13 +13 -
w
A" . A" . A" . A " . A" . A" .
u
Le
0 0
0 V/L' V/Lr
. . . . . .
0 0
0 0 0 0
.L
.
L
112 179 126 atdangle
abcount
46"
36 31 44 43 41 43
.L
52'
.
42' 43" 44" 43"
. 0 .O . L .O . L L . 0 .L . 0
Proband : hallucal area : L : large distal loop R : large whorl
Table 2
Chromosome counts in the proband Chromosome Number Leukocytes Fibroblasts'
+
45
45( ?16)
2
6
46
46(+?16)
47( ?16)
+
Total
4
19 5
69 37
100 59
17
(+?16) mitoses in which the abnormal Ela-like chromosome was present * cells were taken from a first subculture. Total culture age was 20 d
138
ORYE ET AL
Fig. 3. Complete karyotype of the propositus (left) and partial karyotypes (right) of the group E chromosomes and the metacentric extra chromosome (the abnormal chromosome is underlined).
of 15 months, the child was able to roll from supine to the prone position, but still was not able to stand upright, nor hold her head upright without support. Investigations and Results
Analytical findings Peripheral blood analysis, serology and urine examinations were normal. Metabolic screenings (aminoacids) in blood and urine were negative. An electromyography of the facial musculature, an electroencephalography, a brain scan, a subdural puncture and the ophthalmological examination at the age of 14 months because of the facial nerve paralysis, were all normal. X-rays of the skull at the age of 16 months revealed still wide open fontanels and sutures. The interorbital distance was 25 mm (normal values: 18.5 mm k 1.9 mm). X-rays of the hands showed a slight shortening of the medial phalanges of the fifth fingers.
The dermal ridge system Apart from the abnormal creases already mentioned, no peculiar features are to be noted concerning the dermal ridge system of the patient (Table 1). On the fingers, there are seven whorls and three ulnar loops. The axial triradius in both hands is at the normal position and terminates at 13. No absent digital triradii b and c are seen. Chromosome analysis Venous blood for chromosome studies was obtained from the proband on 20 May 1972. One hundred mitoses were counted and analyzed (Table 2) and a modal chromosome number of 47 was found. The extra chromosome was an abnormal E16like chromosome, which had the size of a normal E l 6 chromosome but a more metacentric centromere position (Fig. 3). Both arms of the abnormal chromosome seemed equal in length. In only six mitoses (four
A NEW CASE OF THE TRISOMY 9p SYNDROME
with 46,XX) was the E16-like chromosome not seen. Since 25 mitoses were found which showed the E16-like chromosome and a random loss of one or two of the other chromosomes, these six mitoses must be considered most likely to be artifacts and not a second and normal cell line. A skin biopsy was obtained on 4 October 1973, and fibroblast cultures were established. Fifty nine mitoses were analyzed (Table 2), of which 42 had the abnormal chromosome. Of these 42 mitoses, five had 46 chromosomes and showed an artifactual loss of another chromosome. However, in 17 (28.8 %) mitoses a normal 46,XX chromosome constitution was seen. Apparently, in the skin fibroblasts, a mosaic 46,XX/47,XX,+? 16 is present. Both parents had normal chromosomes. In order to identify the extra E16-like chromosome, an analysis of the G-banding pattern was performed on leukocyte chromosome preparations according to the method of Shiraishi Lk Yosida (1972) and Seabright (1972). Analysis of the R-banding (Carpentier et al. 1972), the Giemsa-llbanding (Bobrow et al. 1972) and the Qbanding (Caspersson et al. 1970) was carried out with the same material. Both arms
139
of the abnormal chromosome show a similar G - and R-banding pattern (Fig. 4). Moreover, this pattern is comparable to the banding pattern of the short arm of chromosome 9. The abnormal chromosome is most probably an isochromosome of the short arm of chromosome 9. The patient’s chromosome constitution is most probably: 46,XX/47,XX,+i(9) (pter + cen + pter). These findings were confirmed by the Qbanding and Giemsa-11-banding studies. In this last technique, the abnormal chromosome showed a strongly stained centromeric region (Fig. 4D). With this technique, the centromeric region is stained only in chromosomes 7 and 10 and especially chromosomes 9. However, the G- and R-banding patterns of the short arm of chromosomes 7 and 10 are completely different from the banding patterns of both arms of the abnormal chromosome. Length measurements of the abnormal chromosome and of the short arm of the normal chromosome 9 were carried out on photographic prints of G-banded mitoses (final enlargement X 3300), using a Zeiss Micro-Videomat, the qualitative and quantitative analyzer of the televised image. The short arm length of the normal chromo-
Fig. 4. The normal and abnormal chromosome 9: (A) in G-banded mitoses according to the technique of Shiraishi 8. Yosida (1972) and ( 8 ) of Seabright (1972): (C) in R-banded mitoses according to the technique of Carpentier et al. (1973): and (D) in Giemsa-11-banded mitoses according to the technique of Bobrow et al. (1972).
140
ORYE ETAL
m
R- BANDING
/J
24-2 21
\
c
13
i
G -BANDING
-9
fv C
21
13
y
i
12
11
13 12
12 f3
ZI
Fig. 5. Reflectodensitometer tracings of the G-banded and R-banded normal and abnormal chromosome 9.
The points of maximal and minimal density of the dark and light bands, respectively, of the short arms are indicated.
some 9 was 5.01 5 0.71 mm. The centromere index of the abnormal chromosome was 49.47 & 0.02 and the total length was 10.18 ? 1.60 mm. The mean arm length was 5.09 ? 0.80 mm. Measurements were also carried out on reflectodensitometer tracings of the normal and abnormal chromosome 9 in G-banded as well as in R-banded
mitoses. These tracings were obtained by using the “Klini-Siekel KSII” scanning reflectodensitometer (developed by J. B. Bijlsma and H. F. France of the Laboratory of Anthropobiology and Human Genetics, Amsterdam). On these tracings, the points of maximal and minimal density of the dark and light bands, respectively, were
Table 3 Mean and standard deviation of the length measurements of the distances between the endpoint of the short arm and the points, corresponding with the maximal and minimal density of the dark and light bands Fespectively, on reflectodensitometer tracings of the short arm of the normal and both arms of the abnormal chromosome 9 in R- and Gbanded mitoses (values expressed as a percentage of total short arm length) R-bands
p 24-2
P 21
P 13
G-bands
P 21
P 13
P 12
i (9 P) (n = 35)
30.1 C 5.2 33.7 f 6.7
48.6 f5.7 50.5 6.4
65.9 f 6.4 67.7 f 6.6
i (9 p) (n = 42)
36.8 f 5.9 39.5 C 6.8
67.9 f 5.8 69.0 C 6.3
81.3 f 7.7 82.6 C 8.9
30.2 C 5.5
48.1 k 7.3
66.4 & 6.7
f 7.9
66.9 f 10.6
79.4 If. 8.2
9 N
(n = 34)
*
9 N
= 39)
36.1
A NEW CASE OF THE TRISOMY 9p SYNDROME
located on the abscissa, as indicated in Fig. 5. The distances between the end point of the short arm and the points corresponding to the light and dark bands were measured and expressed as a percentage of the total short arm length. The values obtained for the light and dark G-bands p13, p12 and p21, and the dark and light Rbands p13, p21 and p24-2 of the short arm of the normal and both arms of the abnormal chromosome 9 are fully comparable (Table 3). These measurements thus give additional evidence for the isochromosome nature of the abnormal chromosome.
Discussion According to Rethor6 et al. (1973), a characteristic clinical entity corresponds to the trisomy of the short arm of chromosome 9. The main clinical features are severe psychomotor retardation, moderate microcephaly, brachycephaly, enophthalmos, antimongoloid slant of the palpebral fissures, mild hypertelorism, protruding ears with abnormal antihelix, a globulous nose, downward slanting mouth and hypoplasia of the phalanges. Some peculiarities of the dermal ridge system are also noted: transverse palmar flexion creases and the absence of a digital triradius or the fusion of triradii b and c. In most of the published cases of this syndrome, a partial or complete trisomy 9p was present, resulting from a balanced chromosome rearrangement in one of. the parents. In our patient, unusual clinical features and a peculiar chromosome aberration were seen. Although the above mentioned clinical features, typical of the trisomy 9p syndrome, were present, our patient seemed to be more severely affected than previously reported cases. Indeed, in addition, our patient exhibited an incomplete harelip on the right side, a cleft of the weak and bony palate, and a peculiar congenital heart de-
141
fect. This is most probably related to the exceptional chromosome findings. Instead of a trisomy 9p, a tetrasomy with mosaicism was found. As far as we know, an isochromosome 9p has not yet been identified. Only one other case has been published in which a tetrasomy with mosaicism was found (Ghymers et al. 1973). Although, as the authors themselves mentioned, the clinical data are incomplete, a congenital heart defect is probably present in this case as well. However, no cleft palate was noted. Since only a limited number of patients with a trisomy 9p is known at present, it may probably be too soon t o conclude that patients with a tetrasomy 9p represent a distinct subtype of the trisomy 9p syndrome, characterized by some more severe congenital anomalies in addition to these of the trisomy 9p syndrome. The chromosome findings in our patient are, in several aspects, comparable to those of the patient of Ghymers et al. (1973). The abnormal chromosome in our case is an isochromosome of the short arm with only a small Giemsa-11 positive centromere region. In the case of Ghymers et al. (1973), the abnormal chromosome most probably resulted from a more complex rearrangement. It consisted of two short arms of chromosome 9 with intercalary, an enlarged Giemsa-11 positive region, which is larger than the corresponding region in the normal chromosome 9. Apart from the centromere position, which is median in our case and submedian in Ghymers’ case, the abnormal chromosomes can be described as (9p,h-, 9p) and (9p,h+, 9p), respectively. Since quantitative changes of the Giemsa-11 positive region in chromosome 9 seem to be compatible with normal development (Abrisqueta et al. 1973), the effective chromosome imbalance in both patients is most probably similar. Another aspect is the mosaicism. In both cases, only abnormal cells were found in the peripheral
142
ORYE ETAL
blood preparations, while in a skin biopsy culture, only normal mitoses were seen in Ghymers' case, a n d normal a n d abnormal mitoses in our case. T h e congenital heart defect with hypoplasia of the pulmonary artery trunk and the origin of both main pulmonary branches is a n unusual cardiological finding. To our knowledge, these supravalvular stenoses have not previously been described in chromosomal syndromes. They a r e found in some rare cases of intrauterine damage t o the fetus (Blancquaert e t al. 1966, Wasserman e t al. 1968, Keutel e t al. 1972, Watson & Miller 1973).
References
Abrisqueta, J. A., I. Cortejarena, A. PerezBousono & M. Perez-Sotelo (1973). Transmission d'un chromosome marqueur (9 q h) dam trois gCnCrations. A n n . Gknkt. 16, 203206. Baccichetti, C. & R. Tenconi (1973). A new case of the trisomy for the short arm of nr 9 chromosome. J . med. Genet. 10, 296-299. Blancquaert, A., C. Dupuis, C. Hooft, J. P. Nuyts & R. Pannier (1966). StCnoses pulmonaires et aortiques postvalvulaires avec facies particulier et retard intellectuel. Acta cardiol. (Brux.) 21, 61 1-643. Bobrow, M., K. Madan & P. L. Pearson (1972). Staining of some specific regions of human chromosomes, particularly the secondary constriction of N o9. Nature N e w Biol. 238, 122-124. Cantu, J. M., L. Buentello & S. Armendares (1971). Trisomie Cp : un nouveau syndrome. Ann. Ge'ne't. 14, 177-186. Carpentier, S., B. Dutrillaux & J. Lejeune (1972). Effet du milieu ionique sur la dCnaturation thermique mCnagCe des chromosomes humains. Ann. Ge'nkt. 15, 203-205. Caspersson, T., L. Zech, C. Johansson & E. J . Modest (1970). Identification of human chromosomes by DNA-binding fluorescent agents. Chromosoma (Bert.) 30, 215-227. Edwards, J . H., M. Fraccaro, P. Davies & R. B. Young (1962). Structural heterozygosis in man: analysis of two families. Ann. hum. Genet. 26, 163-178.
Ghymers, D., B. Hermann, C. Disteche & J. Frederic (1973). T6trasomie partielle du chromosome 9, i I'ttat de mosaique, chez u n enfant porteur de malformations multiples. H u m . Genet. 20, 273-282. Hoehn, H., W. Engel & H. Reinwein (1971). Presumed trisomy for the short arm of chromosome N o 9 not due to inherited translocation. Hum. Genet. 12, 175-181. Keutel, J., G. Jorgensen & P. Gabriel (1972). A new autosomal recessive syndrome: peripheral pulmonary stenoses, brachytelephalangism, neural hearing loss and abnormal cartilage calcificationdossification. Birth Defects: Original Article Series VIII, 60-68. Lejeune, J., R. Berger, M. 0. RethorC, Ch. Salmon & M. Kaplan (1966). Translocation Cc/F familiale, dkterminant une trisomie pour le bras court du chromosome 12. Ann. Gkne't. 11, 88-94. Lord, P. M., M. D. Casey & B. M. Laurence (1967). A new translocation between chromosomes in the 6-12 and 21-22 groups. J . med. Genet. 4, 169-176. Newton, M. S., C. Cunningham, P. A. Jacobs, W. H. Price & I. A. Fraser (1972). Chromosome survey of a hospital for the mentally subnormal. Part 2: Autosome abnormalities. Clin. Genet. 3, 226-248. Pryor, H. B. (1969). Objective measurement of interpupillary distance. Pediatrics 44, 973977. RethorC, M. O., H. Hoehn, H. D. Rott, J. Couturier, B. Dutrillaux & J. Lejeune (1973). Analyse de la trisomie 9 p par dknaturation mCnag6e. A propos d'un nouveau cas. H u m . Genet. 18, 129-138. RethorC, M. O., L. Larget-Piet, D. Abonyi, M. Boeswillwald, R. Berger, S. Carpentier, J. Cruveiller, B. Dutrillaux, J. Lafourcade, M. Penneau & J. Lejeune (1970). Sur quatre cas de trisomie pour le bras court du chromosome 9. Individualisation d'une nouvelle entiti morbide. Ann. Ge'ne't. 13, 217-232. Rott, H. D., G. Schwanitz K. P. Grosse (1971). Partielle Trisomie Cq bei balancierter B,/Cq- Translokation bei der Mutter. Z . Kinderheilk. 109, 293-299. Seabright, M. (1972). The use of proteolytic enzymes for the mapping of structural rearrangements in the chromosomes of man. Chrornosoma (Bert.) 36, 204-210. Shiraishi, Y. & T. H. Yosida (1972). Banding pattern analysis of human chromosomes by use of a urea treatment technique. Chromosoma (Berl.) 37, 75-83. (&
A NEW CASE OF THE TRISOMY 9p SYNDROME
Wasserman, M. P., P. J. Varghese & R. D. Rowe (1968). The evolution of pulmonary arterial stenosis associated with congenital rubella. Amer. Heart J . 76, 638444. Watson, G. H. & V. Miller (1973). Arteriohepatic dysplasia. Familial pulmonary artery stenosis with neonatal liver disease. Arch. Dis. Childh. 48. 459-466.
Address: Dr. Sc. Edward Orye Laboratory o f Cytogenetics Department o f Pediatrics (Dir.: Prof. Dr. C . H o o f t ) Rijksuniversiteit Gent D e Pintelaan 135 B - 9000 Ghent Belgium
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