Hum. Genet. 38,245--248 (1977) © by Springer-Verlag 1977

Partial 9q Trisomy Associated with a 9,21 Translocation Yves C h a m l a , C a t h e r i n e Bilbeissi, M a r g u e r i t e M i c h e a u , a n d J a c q u e s Battin H6pital des Enfants, 168 cours de l'Argonne, F-33077 Bordeaux Cedex, France

S u m m a r y . A new case o f p a r t i a l t r i s o m y 9q was f o u n d in a child p r e s e n t i n g t w o de n o v o a b e r r a t i o n s : a deletion o f the long arms o f 9 a n d a 9,21 t r a n s l o c a t i o n . A tentative cytogenetic e x p l a n a t i o n is p u t forward.

introduction P a r t i a l 9q trisomies have been described a n d the related clinical features a l r e a d y d e l i n e a t e d as a s y n d r o m e (Centerwall et al., 1976; T u r l e a u et al., 1975). T o o u r k n o w l e d g e all the r e p o r t e d cases resulted f r o m p a r e n t a l transl0cations. M o r e o v e r the de n o v o f o r m a t i o n o f two c h r o m o s o m a l a b e r r a t i o n s is u n c o m m o n . The p r e s e n t p a p e r r e p o r t s the s i m u l t a n e o u s occurrence o f a deleted 9q a n d a t r a n s l o c a t e d 9,21 c h r o m o s o m e s in a 8 - m o n t h - o l d infant.

Case Report F.G., a male, is the first born of healthy and nonconsanguineous parents, aged respectively 22 and 18 at his birth. Delivery was uneventful after a full-term pregnancy. Birth weight was 3250 g. On admission at 8 months of age, weight was 8500 g, height 66 cm, head circumference 45 cm. The psychomotor development was retarded and a marked hypotonia was observed, with multiple abnormalities: hypertelorism, bilateral epicanthus, convergent squint in the left eye, low-set ears with large lobes, down-slanting corners of mouth, with short philtrum, thick lips, receding chin, low-set thumbs with malformations of their terminal phalanges, bilateral single palmar crease, scoliosis, engulfed penis. The infant had always manifested digestive disorders and vomiting.

Cytogenetic Studies C h r o m o s o m e analyses were p e r f o r m e d on b l o o d culture. T - b a n d i n g was c a r r i e d o u t b y the fluorescence m e t h o d o f D u t r i l l a u x (1973) after heat t r e a t m e n t a n d staining with acridine orange. R b a n d s were o b t a i n e d b y h e a t t r e a t m e n t in

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Fig. 1. Partial karyotypes of the propositus and his parents. (a) R-banding. (b) CT procedure. c: centromeres, s: satellites, s c : secondary constrictions

Hanks' solution at 87°C. The CT-banding procedure of Chamla and Ruffi6 (1976) was performed 2 years later on previously stained slides, as this technique enhances satellite marking on old preparations and provides a distinct pattern for C bands and secondary constrictions. The karyotype of the propositus shows one normal chromosome 9, one chromosome 9 deleted for its q33 and q34 bands, and a translocated chromosome initially considered as 9q21q, the rest of the karyotype being normal. It was thus considered to be 46,XY, t(9q;21q),del(9)(q32), the trisomy involving the 9ql 1-9q32 region. A thorough examination of the R bands in the translocated chromosome reveals a dark band located in the centromeric area (Fig. 1, large arrow). T-banding failed to discover the deleted terminal 9q34 band. However, by this technique, satellitelike dots are evidenced on the subcentromeric region of the translocated chromosome (Fig. 2, arrow). With C-banding, the normal and the deleted chromosomes 9 show centromeric staining and large secondary con-

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Fig. 2. Partial karyotype of the propositus, fluorescence staining with acridine orange. Arrow indicates satellite marking strictions, but no centromeric staining senso strictu is seen on the translocated chromosome, on which the subcentromeric marking is dot-shaped. Both parents have a normal karyotype and both of them have large secondary constrictions on chromosomes 9. As for the top telomeric regions of the G-group chromosomes, satellites are evidenced by the CT technique in the cells of the father only. The propositus inherited from his mother a free G chromosome which is totally unstained for its centromere and satellites.

Discussion With respect to clinical matters it should be noted that most of the abnormalities observed in our patient were reported independently by Sutherland et al. (1976) in a trisomy 9 and particularly by Centerwall et al. (1975) in a case of trisomy for a del(9)(q22) chromosome, which he compared to the trisomy 9p Syndrome delineated by Rethor6 et al. (1970). A few only of these abnormalities are assigned Table 1. Comparative features of patients presenting the closest 9q trisomic regions Centerwall et al. (1975)

Turleau et al. (1975) Case 1

Present case

Trisomic segment

9(ql 1-q22)

9(ql 1-q33)

9(qll-q32)

General condition

Growth d e l a y e d

Psychomotor development Psychomotor development severely retarded retarded. Hypotonia

Inner canthal distance

Slight hypertelorism

Hypotelorism

Hypertelorism

Eyes

Mongoloid slants

Deeply set. Strabismus Bilateral epicanthus

Strabismus Bilateral epieanthus

Ears

Low-set

Normal

Low-set

Chin

Receding

Receding

Receding

Mouth

Down-slanting corners Thin lips

Normal, small-sized

Down-slanting corners Thick lips

Hands

Low-set thumbs Single palmar creases

Clutched fingers Normal creases

Low-set thumbs Single palmar creases

Genitalia

Engulfed penis

Normal (female)

Engulfed penis

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by Turleau et al. (1975) to the trisomy o f the 9q3 lq32 region. In fact our patient is m o r e similar to the first case o f Turleau et al., who was trisomic for the 9ql lq33 segment. We are aware o f the recent publication o f ~ubrt (1976) in which the trisomy 9 involves the q32qter segment. In Table 1, we c o m p a r e our patient's main clinical features only with those o f the two closest cytogenetic cases. The cytogenetic finding in our translocated c h r o m o s o m e is unusual. H o w ever, the following hypothesis can be proposed: The lack o f a real C b a n d on this c h r o m o s o m e ascertains a centromeric deletion for the part belonging to the 9, and suggests that the translocated 21 is entire, with p o o r C bands and maintenance o f medium-sized satellites, which are confirmed by fluorescence staining, and m a y be represented by the dark subcentromeric R band.

Acknowledgements. We are indebted to Dr.M. Accardi from Bordeaux who allowed the observation of his patient. Dr. B. Noel from Chamb6ry helped us with the fluorescence analysis.

References Centerwall, W. R,, Mayeski, C. A., Cha, C. C.: Trisomy 9q-. A variant of the 9p trisomy syndrome. Humangenetik 29, 91--98 (1975) Chamla, Y., Ruffi6, M.: Production of C and T bands in human mitotic chromosomes after heat treatment. Hum. Genet. 34, 213--216 (1976) Dutrillaux, B.: Nouveau syst~me de marquage chromosomique: les bandes T. Chromosoma (Berl.) 41,395--402 (1973) Rethor6, M. O., Larget-Piet, L., Abonyi, D., Boeswilwald, N., Berger, R., Carpentier, S., Cruveiller, J., Dutrillaux, B., Lafourcade, J., Penneau, M., Lejeune, J.: Sur quatre cas de trisomie pour le bras court du chromosome 9. Individualisation d'une nouvelle entit6 morbide. Ann. G6n~t. 13, 217--232 (1970) ~ubrt, I., Janovsk~,, M., Jodl, J.: Partial trisomy 9q- chromosomal syndrome. Hum. Genet. 34, 151--154 (1976) Sutherland, G. R., Carter, R. F., Morris, L. L.: Partial and complete trisomy 9. Delineation of a trisomy 9 syndrome. Hum. Genet. 32, 133--140 (1976) Turleau, C., de Grouchy, J., Chavin-Colin, F., Roubin, M., Brissaud, P. E., Repess6, G., Safar, A., Borniche, P.: Partial trisomy 9q: A new syndrome. Humangenetik 29, 233--241 (1975)

Received November 3, 1976 / April 22, 1977

Partial 9q trisomy associated with a 9,21 translocation.

Hum. Genet. 38,245--248 (1977) © by Springer-Verlag 1977 Partial 9q Trisomy Associated with a 9,21 Translocation Yves C h a m l a , C a t h e r i n e...
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