Eur J Pediatr DOI 10.1007/s00431-013-2243-9
SHORT COMMUNICATION
Leopard syndrome: a report of five cases from one family in two generations Fatima Begić & Husref Tahirović & Mediha Kardašević & Ingrid Kalev & Kai Muru
Received: 17 November 2013 / Accepted: 11 December 2013 # Springer-Verlag Berlin Heidelberg 2014
Abstract This is the first reported family with Leopard syndrome (LS) from Bosnia and Herzegovina. We report five cases of LS from two generations of the same family. In the present series of patients from one family, all patients carry the same recurrent mutation Y279C in the PTPN11 gene, exhibiting different phenotypes and a variable expression of multiple lentigines. The diagnosis may be on clinical basis as the diagnostic clues of LS are: multiple lentigines and cafè-au-lait-spots, short stature, distinctive face, congenital heart disease, conduction abnormalities, abnormal genitalia, and sensorineural deafness. Conclusion: the clinical diagnosis of LS should be molecularly confirmed in the patient. Keywords LEOPARD syndrome . PTPN11 gene . Y279C . SHP-2 . Multiple lentigines
F. Begić : M. Kardašević Department of Pediatrics, General Hospital “Dr. Irfan Ljubijankić”, Bihać, Bosnia and Herzegovina H. Tahirović (*) Department of Medical Sciences, Academy of Sciences and Arts of Bosnia and Herzegovina, Bistrik 7, 71000 Sarajevo, Bosnia and Herzegovina e-mail: [email protected] H. Tahirović e-mail: [email protected] I. Kalev Department of Human Biology and Genetics, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia K. Muru Department of Pediatrics, University of Tartu, Tartu, Estonia
Introduction Leopard syndrome (LS; OMIM 151100) is a rare multisystemic disorder, inherited as an autosomal dominant trait, with full penetrance and variable expressivity. LEOPARD is an acronym for the major features that characterize the syndrome: multiple Lentigines, Electrocardiographic conduction defects, Ocular hypertelorism, Pulmonary stenosis, genital Abnormality, Retardation of growth, and sensorineural Deafness [2]. About 200 patients have so far been reported worldwide, although LS seems to be underdiagnosed or misdiagnosed due to its mild features and/or the absence of Lentiginosis [9]. LS is caused by heterozygous missense mutations in the PTPN11 gene (12q22-qter, which includes 15 exons) exons 7, 12, and 13 in about 85 % of cases. The recurrent mutations in exons 7 (Tyr279Cys) and 12 (Thr468Met) are highly specific for LS [1, 4, 8] and occur in about 65 % of cases [9]. If one parent is affected, there is a 50 % recurrence risk [9]. We report five cases of Leopard syndrome from two generations of the same family from Bosnia and Herzegovina, with the same recurrent mutation Y279C in the PTPN11 gene, exhibiting different phenotypes and a variable expression of multiple lentigines.
Patients and methods The patients were referred to the Department of Pediatrics of the “Dr. Irfan Ljubijankić” General Hospital, Bihać, Bosnia and Herzegovina. Clinical and laboratory data for these four cases were gathered by a pediatrician with the standard datasheet for LS from their medical records. Data for the father of our patients were obtained on the basis of anamnestic data and clinical findings. All of the patients in this series had the final diagnosis of LEOPARD syndrome, confirmed by
Eur J Pediatr
I:1
The sequencing analysis of the PTPN11 gene of the family members revealed a frequent missense mutation (c.836A>G) in exon 7 (Y279C) of the PTPN11 gene of father and his four children, but not of the mother and grandparents (Fig. 3). The absence of the same gene in the DNA analyses from the grandparents revealed that the mutation occurred de novo in their son (II:1) and was inherited from father to the third generation (III:1, III:2, III:3, III:4).
I:2
II:1
II:2
Case summaries of patients III:1
III:2
III:3
III:4
Fig. 1 Family pedigree; colored symbols—affected family members
molecular analysis. Informed written consent was obtained from all the patients enrolled in the study, according to the protocol of the WMA Declaration of Helsinki—Ethical Principles for Medical Research Involving Human Subjects [12]. Analysis of the PTPN11 gene exons 7, 12, and 13 and their intron–exon boundaries was accomplished by PCR (polymerase chain reaction) with primer sequences and PCR conditions, which have been described previously [6] and subsequent direct bi-directional sequencing and re-sequencing of the amplified fragments on an ABI 377 autosequencer (Applied Biosystems, Foster City, CA, USA) using the Big Dye Terminator Cycle Sequencing Ready Reaction Kit version 1.1. (Applied Biosystems, USA). The sequences were aligned and compared with the reference sequence for genomic DNA (GenBank NT_009775) for analysis of the variants for each patient.
Results In this study, the pedigree consisting of three generations was included. We investigated all the family members phenotypically and genotypically from one pedigree member (Fig. 1).
Data of personal history in five family members are summarized in Table 1. Clinical findings on the day of examination At the time of investigation, the father (II:1) of the patients (at the age of 46 years) presented diffuse pigmentation throughout his body, more densely spaced in the proximal part of the body. The diameter of the lentigines was up to 5 mm. He also presented mild pectus excavatum (Fig. 2a). The elder son (III:2) presented at the age of 17.9 years with visible diffuse dark brown lentigines up to 5 mm (Fig. 2b). He also had kyphoscoliosis of the cervico-thoracic spine, diagnosed at the age of 1 year. The elder daughter (III:1) at the age of 16.8 years presented visible skin macules (diameter up to 5 mm) throughout the body especially in the region of the thorax and upper extremities, as well as on the face around the lips. She also presented ocular hypertelorism, kyphosis of the cervico-thoracic spine and scapulae alatae (Fig. 2c). Her kyphosis was diagnosed at the age of 3 years. The younger son (III:4) at the age of 12.6 years presented diffuse dark brown lentigines all over the body with diameter up to 5 mm. He had some dysmorphic features: antimongoloid palpebral fissure, hypertelorism, ptosis, low-set ears, pectus excavatum, scapulae alatae, and
Table 1 Summarized data of personal history in five family members Data of personal history
Pregnancy of the mother Labor Apgar at first minute Birth weight (g) Birth length (cm) Head circumference at birth (cm) Anomalies at birth Appeared of first lentigines (months of life) Deficit growth hormone Psychomotor development
Members of family Father of patients
Elder son
Elder daughter
Younger daughter
Younger son
Normal* Normal Not known Not known Not known Not known − 1st − Normal
Normal* Normal 9 2,750 45 33 − 2nd − Normal
Normal* Normal 10 3,100 54 33.5 − 2nd − Normal
Normal* Normal 9 2,270 45 32.5 − 8th − Normal
Normal* Normal 9 2,720 46 32.5 Cleft palate 2nd + Normal
*Not controlled; + = feature present; − = feature absent.
Eur J Pediatr
Fig. 2 Photographs of five family members. a Father of the patients, at the age of 46 years; b elder son, at the age of 17 years; c elder daughter, at the age of 16 years; d younger son, at the age of 12 years; e younger daughter, at the age of 14 years. The photos show variable expression of multiple lentigines and phenotype
scoliosis vertebrae thoracalis (Fig. 2d), and he also had dysplasia of the costae primae, atrial septal aneurysm, pedes plana, and poorly understandable nasal speech. He also had a congenital anomaly–cleft palate, which was successfully surgically treated at the age of 2 years. The younger daughter (III:3) presented at the age of 14.3 years diffuse lentigines all over the body, more densely spaced in the proximal part of the hull, with diameter up 15 cm. She had dysmorphic features, such as ocular hypertelorism, ptosis, dysmorphic ears, irregularly shaped left clavicle, pectus excavatum, scapulae alatae, and kyphosis in the area of the thoracic region of the spine (Fig. 2e). She also had systolic murmur of the II/6 tricuspid aortic valve with a thickened rim of the right coronary cuspis, malrotation of the right pelvis, and ectopic left kidney. Fig. 3 Electrophoregrams showing the heterozygous missense mutation c.836 A>G (p.Tyr279Cys) in PTPN11 gene exon 7 in patients 1, 2, 3, 4 (siblings), and 6 (father). Sequences from healthy control sample and patient 5 (mother) as well as from the grandparents indicate wild-type genotypes
Genomic DNA analyses In the PTPN11 gene, we found exon 7 at cDNA position 836 by direct bi-directional sequencing a heterozygous nucleotide substitution from A to G (transition) altering the amino acid tyrosine to cysteine [c. 836 A→G/p. Tyr279Cys (Y279C)] in all five patients. This mutation is located in the phosphotyrosine phosphatase domain of the SHP-2 protein and has previously been described in patients with LS [1, 3]. Therefore, the diagnosis of LS for all patients could be confirmed (Fig. 3).
Discussion Here, we present five family members from one family with full-blown but variable pictures of LS. All affected family
Normal sequence from control patient
Mutated sequence from patient no 3
Normal sequence from patient no 5
Mutated sequence from patient no 4
Mutated sequence from patient no 6
Mutated sequence from patient no 1
Mutated sequence (reverse strand) from pt no 2
Normal sequence from patient AS1, a grandparent Normal sequence from patient AA1, a grandparent
Eur J Pediatr
members have the key feature of LS—multiple lentigines from the first month of life. The location and appearance of the lentigines were classical. Short stature is one of the distinct features of LS. At the time of clinical examination, almost all the affected family members (III:2, III:3, III:4) showed short stature, height was normal in only one (III:1). Interestingly, the younger daughter (III:3) along with short stature had also low birth weight and length, while her brothers had normal birth parameters. In our series only one affected family member, the younger son (III:4), had growth hormone deficiency. Namely, at the age of 10, his height was 106 cm (25 cm below P3) and bone age less than chronological age. Other affected family members with short stature were not examined for growth hormone deficiency. According to Martínez-Quintana and RodríguezGonzález [7], growth retardation is not related to endocrine problems or systemic diseases in LS. All our patients have distinct skeletal anomalies: kyphoscoliosis in different degrees, and there is a tendency to develop thoracic kyphosis with age [8]. However, their affected father does not have kyphoscoliosis, at least by the age of 46 years. Hence, there must be different factors that determine skeletal anomalies. Cardiac problems, such as congenital heart defect (most often pulmonic stenosis) and cardiomyopathy, are a feature of LS. None of our family members has a diagnosed congenital heart defect such as pulmonic stenosis, only the younger daughter has a minor heart problem, which does not need any special treatment. The absence of heart problems gives better prognosis for LS. Sensoneural deafness is one of the features of LS. In our family with variable phenotypes, deafness was not diagnosed in any of them. There must be some additional factors to develop the feature. The clinical LS diagnosis in all affected family members was confirmed with the identification of a heterozygous recurrent mutation c.836 A→G/p.Y279C in the exon 7 of PTPN11 gene. The analysis of the PTPN11 gene of LS specific exons 7, 12, and 13 revealed a disease-causing recurrent mutation c.836 A→G/p.Y279C in the exon 7 of the PTPN11 gene codes for SHP-2, the cytoplasmic nonreceptor protein tyrosine phosphatase, which is predicted to contain 593 amino acid residues. Probably, the mutation Y279C affects residues in the catalytic domain of phosphotyrosine phosphatase and results in reduced protein tyrosine phosphatase activity [5, 10]. Although all the affected family members have the same mutation and fulfilled the current diagnostic criteria proposed by Voron et al. [11], they have different phenotypes. This suggests that additional factors (environmental or genetic) are also involved in the expression of the LS. Although the paternal grandparents of our patients had no clinical characteristics that would indicate LEOPARD syndrome, it is
necessary to perform DNA analysis to rule out the presence of this disease. Limitations of study Our patients were not adequately clinically tested because they were tested in the general hospital, where the possibilities for complex clinical trials are limited. Conflict of interest The authors declare that they have no conflict of interest. This study was not sponsored by any external organization.
References 1. Digilio MC, Conti E, Sarkozy A, Mingarelli R, Dottorini T, Marino B, Pizzuti A, Dallapiccola B (2002) Grouping of multiple-lentigines/ LEOPARD and Noonan syndromes on the PTPN11 gene. Am J Hum Genet 71:389–394 2. Gelb BD, Tartaglia M (2007) LEOPARD syndrome. In: Pagon RA, Adam MP, Bird TD, Dolan CR, Fong CT, Stephens K (eds) GeneReviews™ [Internet]. University of Washington, Seattle, pp 1993–2013 3. Kalev I, Muru K, Teek R, Zordania R, Reimand T, Köbas K, Õunap K (2010) LEOPARD syndrome with recurrent PTPN11 mutation Y279C and different cutaneous manifestations: two case reports and a review of the literature. Eur J Pediatr 169:469–473 4. Keren B, Hadchouel A, Saba S, Sznajer Y, Bonneau D, Leheup B, Boute O, Gaillard D, Lacombe D, Layet V, Marlin S, Mortier G, Toutain A, Beylot C, Baumann C, Verloes A, Cavé H (2004) French Collaborative Noonan Study Group. PTPN11 mutations in patients with LEOPARD syndrome: a French multicentric experience. J Med Genet 41:e117 5. Kontaridis MI, Swanson KD, David FS, Barford D, Neel BG (2006) PTPN11 (Shp2) mutations in LEOPARD syndrome have dominant negative, not activating, effects. J Biol Chem 281:6785–6792 6. Kosaki K, Suzuki T, Muroya K, Hasegawa T, Sato S, Matsuo N, Kosaki R, Nagai T, Hasegawa Y, Ogata T (2002) PTPN11 (proteintyrosine phosphatase, nonreceptor-type 11) mutations in seven Japanese patients with Noonan syndrome. J Clin Endocrinol Metab 87:3529–3533 7. Martínez-Quintana E, Rodríguez-González F (2012) LEOPARD syndrome caused by Tyr279Cys mutation in the PTPN11 gene. Mol Syndromol 2:251–253 8. Sarkozy A, Conti E, Digilio MC, Marino B, Morini E, Pacileo G, Wilson M, Calabrò R, Pizzuti A, Dallapiccola B (2004) Clinical and molecular analysis of 30 patients with multiple lentigines LEOPARD syndrome. J Med Genet 41:e68 9. Sarkozy A, Digilio MC, Dallapiccola B (2008) Leopard syndrome. Orphanet J Rare Dis 3:13 10. Tartaglia M, Martinelli S, Stella L, Bocchinfuso G, Flex E, Cordeddu V, Zampino G, Burgt I, Palleschi A, Petrucci TC, Sorcini M, Schoch C, Foa R, Emanuel PD, Gelb BD (2006) Diversity and functional consequences of germline and somatic PTPN11 mutations in human disease. Am J Hum Genet 78:279–290 11. Voron DA, Hatfield HH, Kalkhoff RK (1976) Multiple lentigines syndrome. Case report and review of the literature. Am J Med 60:447–456 12. World Medical Association [homepage on the Internet]. Declaration of Helsinki—ethical principles for medical research involving human subjects [cited 2013 January 24]. Available from: http://www.wma. net/en/30publications/10policies/b3/index.html.pdf?print-mediatype&footer-right=[page]/[toPage]
SHORT COMMUNICATION
Leopard syndrome: a report of five cases from one family in two generations Fatima Begić & Husref Tahirović & Mediha Kardašević & Ingrid Kalev & Kai Muru
Received: 17 November 2013 / Accepted: 11 December 2013 # Springer-Verlag Berlin Heidelberg 2014
Abstract This is the first reported family with Leopard syndrome (LS) from Bosnia and Herzegovina. We report five cases of LS from two generations of the same family. In the present series of patients from one family, all patients carry the same recurrent mutation Y279C in the PTPN11 gene, exhibiting different phenotypes and a variable expression of multiple lentigines. The diagnosis may be on clinical basis as the diagnostic clues of LS are: multiple lentigines and cafè-au-lait-spots, short stature, distinctive face, congenital heart disease, conduction abnormalities, abnormal genitalia, and sensorineural deafness. Conclusion: the clinical diagnosis of LS should be molecularly confirmed in the patient. Keywords LEOPARD syndrome . PTPN11 gene . Y279C . SHP-2 . Multiple lentigines
F. Begić : M. Kardašević Department of Pediatrics, General Hospital “Dr. Irfan Ljubijankić”, Bihać, Bosnia and Herzegovina H. Tahirović (*) Department of Medical Sciences, Academy of Sciences and Arts of Bosnia and Herzegovina, Bistrik 7, 71000 Sarajevo, Bosnia and Herzegovina e-mail: [email protected] H. Tahirović e-mail: [email protected] I. Kalev Department of Human Biology and Genetics, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia K. Muru Department of Pediatrics, University of Tartu, Tartu, Estonia
Introduction Leopard syndrome (LS; OMIM 151100) is a rare multisystemic disorder, inherited as an autosomal dominant trait, with full penetrance and variable expressivity. LEOPARD is an acronym for the major features that characterize the syndrome: multiple Lentigines, Electrocardiographic conduction defects, Ocular hypertelorism, Pulmonary stenosis, genital Abnormality, Retardation of growth, and sensorineural Deafness [2]. About 200 patients have so far been reported worldwide, although LS seems to be underdiagnosed or misdiagnosed due to its mild features and/or the absence of Lentiginosis [9]. LS is caused by heterozygous missense mutations in the PTPN11 gene (12q22-qter, which includes 15 exons) exons 7, 12, and 13 in about 85 % of cases. The recurrent mutations in exons 7 (Tyr279Cys) and 12 (Thr468Met) are highly specific for LS [1, 4, 8] and occur in about 65 % of cases [9]. If one parent is affected, there is a 50 % recurrence risk [9]. We report five cases of Leopard syndrome from two generations of the same family from Bosnia and Herzegovina, with the same recurrent mutation Y279C in the PTPN11 gene, exhibiting different phenotypes and a variable expression of multiple lentigines.
Patients and methods The patients were referred to the Department of Pediatrics of the “Dr. Irfan Ljubijankić” General Hospital, Bihać, Bosnia and Herzegovina. Clinical and laboratory data for these four cases were gathered by a pediatrician with the standard datasheet for LS from their medical records. Data for the father of our patients were obtained on the basis of anamnestic data and clinical findings. All of the patients in this series had the final diagnosis of LEOPARD syndrome, confirmed by
Eur J Pediatr
I:1
The sequencing analysis of the PTPN11 gene of the family members revealed a frequent missense mutation (c.836A>G) in exon 7 (Y279C) of the PTPN11 gene of father and his four children, but not of the mother and grandparents (Fig. 3). The absence of the same gene in the DNA analyses from the grandparents revealed that the mutation occurred de novo in their son (II:1) and was inherited from father to the third generation (III:1, III:2, III:3, III:4).
I:2
II:1
II:2
Case summaries of patients III:1
III:2
III:3
III:4
Fig. 1 Family pedigree; colored symbols—affected family members
molecular analysis. Informed written consent was obtained from all the patients enrolled in the study, according to the protocol of the WMA Declaration of Helsinki—Ethical Principles for Medical Research Involving Human Subjects [12]. Analysis of the PTPN11 gene exons 7, 12, and 13 and their intron–exon boundaries was accomplished by PCR (polymerase chain reaction) with primer sequences and PCR conditions, which have been described previously [6] and subsequent direct bi-directional sequencing and re-sequencing of the amplified fragments on an ABI 377 autosequencer (Applied Biosystems, Foster City, CA, USA) using the Big Dye Terminator Cycle Sequencing Ready Reaction Kit version 1.1. (Applied Biosystems, USA). The sequences were aligned and compared with the reference sequence for genomic DNA (GenBank NT_009775) for analysis of the variants for each patient.
Results In this study, the pedigree consisting of three generations was included. We investigated all the family members phenotypically and genotypically from one pedigree member (Fig. 1).
Data of personal history in five family members are summarized in Table 1. Clinical findings on the day of examination At the time of investigation, the father (II:1) of the patients (at the age of 46 years) presented diffuse pigmentation throughout his body, more densely spaced in the proximal part of the body. The diameter of the lentigines was up to 5 mm. He also presented mild pectus excavatum (Fig. 2a). The elder son (III:2) presented at the age of 17.9 years with visible diffuse dark brown lentigines up to 5 mm (Fig. 2b). He also had kyphoscoliosis of the cervico-thoracic spine, diagnosed at the age of 1 year. The elder daughter (III:1) at the age of 16.8 years presented visible skin macules (diameter up to 5 mm) throughout the body especially in the region of the thorax and upper extremities, as well as on the face around the lips. She also presented ocular hypertelorism, kyphosis of the cervico-thoracic spine and scapulae alatae (Fig. 2c). Her kyphosis was diagnosed at the age of 3 years. The younger son (III:4) at the age of 12.6 years presented diffuse dark brown lentigines all over the body with diameter up to 5 mm. He had some dysmorphic features: antimongoloid palpebral fissure, hypertelorism, ptosis, low-set ears, pectus excavatum, scapulae alatae, and
Table 1 Summarized data of personal history in five family members Data of personal history
Pregnancy of the mother Labor Apgar at first minute Birth weight (g) Birth length (cm) Head circumference at birth (cm) Anomalies at birth Appeared of first lentigines (months of life) Deficit growth hormone Psychomotor development
Members of family Father of patients
Elder son
Elder daughter
Younger daughter
Younger son
Normal* Normal Not known Not known Not known Not known − 1st − Normal
Normal* Normal 9 2,750 45 33 − 2nd − Normal
Normal* Normal 10 3,100 54 33.5 − 2nd − Normal
Normal* Normal 9 2,270 45 32.5 − 8th − Normal
Normal* Normal 9 2,720 46 32.5 Cleft palate 2nd + Normal
*Not controlled; + = feature present; − = feature absent.
Eur J Pediatr
Fig. 2 Photographs of five family members. a Father of the patients, at the age of 46 years; b elder son, at the age of 17 years; c elder daughter, at the age of 16 years; d younger son, at the age of 12 years; e younger daughter, at the age of 14 years. The photos show variable expression of multiple lentigines and phenotype
scoliosis vertebrae thoracalis (Fig. 2d), and he also had dysplasia of the costae primae, atrial septal aneurysm, pedes plana, and poorly understandable nasal speech. He also had a congenital anomaly–cleft palate, which was successfully surgically treated at the age of 2 years. The younger daughter (III:3) presented at the age of 14.3 years diffuse lentigines all over the body, more densely spaced in the proximal part of the hull, with diameter up 15 cm. She had dysmorphic features, such as ocular hypertelorism, ptosis, dysmorphic ears, irregularly shaped left clavicle, pectus excavatum, scapulae alatae, and kyphosis in the area of the thoracic region of the spine (Fig. 2e). She also had systolic murmur of the II/6 tricuspid aortic valve with a thickened rim of the right coronary cuspis, malrotation of the right pelvis, and ectopic left kidney. Fig. 3 Electrophoregrams showing the heterozygous missense mutation c.836 A>G (p.Tyr279Cys) in PTPN11 gene exon 7 in patients 1, 2, 3, 4 (siblings), and 6 (father). Sequences from healthy control sample and patient 5 (mother) as well as from the grandparents indicate wild-type genotypes
Genomic DNA analyses In the PTPN11 gene, we found exon 7 at cDNA position 836 by direct bi-directional sequencing a heterozygous nucleotide substitution from A to G (transition) altering the amino acid tyrosine to cysteine [c. 836 A→G/p. Tyr279Cys (Y279C)] in all five patients. This mutation is located in the phosphotyrosine phosphatase domain of the SHP-2 protein and has previously been described in patients with LS [1, 3]. Therefore, the diagnosis of LS for all patients could be confirmed (Fig. 3).
Discussion Here, we present five family members from one family with full-blown but variable pictures of LS. All affected family
Normal sequence from control patient
Mutated sequence from patient no 3
Normal sequence from patient no 5
Mutated sequence from patient no 4
Mutated sequence from patient no 6
Mutated sequence from patient no 1
Mutated sequence (reverse strand) from pt no 2
Normal sequence from patient AS1, a grandparent Normal sequence from patient AA1, a grandparent
Eur J Pediatr
members have the key feature of LS—multiple lentigines from the first month of life. The location and appearance of the lentigines were classical. Short stature is one of the distinct features of LS. At the time of clinical examination, almost all the affected family members (III:2, III:3, III:4) showed short stature, height was normal in only one (III:1). Interestingly, the younger daughter (III:3) along with short stature had also low birth weight and length, while her brothers had normal birth parameters. In our series only one affected family member, the younger son (III:4), had growth hormone deficiency. Namely, at the age of 10, his height was 106 cm (25 cm below P3) and bone age less than chronological age. Other affected family members with short stature were not examined for growth hormone deficiency. According to Martínez-Quintana and RodríguezGonzález [7], growth retardation is not related to endocrine problems or systemic diseases in LS. All our patients have distinct skeletal anomalies: kyphoscoliosis in different degrees, and there is a tendency to develop thoracic kyphosis with age [8]. However, their affected father does not have kyphoscoliosis, at least by the age of 46 years. Hence, there must be different factors that determine skeletal anomalies. Cardiac problems, such as congenital heart defect (most often pulmonic stenosis) and cardiomyopathy, are a feature of LS. None of our family members has a diagnosed congenital heart defect such as pulmonic stenosis, only the younger daughter has a minor heart problem, which does not need any special treatment. The absence of heart problems gives better prognosis for LS. Sensoneural deafness is one of the features of LS. In our family with variable phenotypes, deafness was not diagnosed in any of them. There must be some additional factors to develop the feature. The clinical LS diagnosis in all affected family members was confirmed with the identification of a heterozygous recurrent mutation c.836 A→G/p.Y279C in the exon 7 of PTPN11 gene. The analysis of the PTPN11 gene of LS specific exons 7, 12, and 13 revealed a disease-causing recurrent mutation c.836 A→G/p.Y279C in the exon 7 of the PTPN11 gene codes for SHP-2, the cytoplasmic nonreceptor protein tyrosine phosphatase, which is predicted to contain 593 amino acid residues. Probably, the mutation Y279C affects residues in the catalytic domain of phosphotyrosine phosphatase and results in reduced protein tyrosine phosphatase activity [5, 10]. Although all the affected family members have the same mutation and fulfilled the current diagnostic criteria proposed by Voron et al. [11], they have different phenotypes. This suggests that additional factors (environmental or genetic) are also involved in the expression of the LS. Although the paternal grandparents of our patients had no clinical characteristics that would indicate LEOPARD syndrome, it is
necessary to perform DNA analysis to rule out the presence of this disease. Limitations of study Our patients were not adequately clinically tested because they were tested in the general hospital, where the possibilities for complex clinical trials are limited. Conflict of interest The authors declare that they have no conflict of interest. This study was not sponsored by any external organization.
References 1. Digilio MC, Conti E, Sarkozy A, Mingarelli R, Dottorini T, Marino B, Pizzuti A, Dallapiccola B (2002) Grouping of multiple-lentigines/ LEOPARD and Noonan syndromes on the PTPN11 gene. Am J Hum Genet 71:389–394 2. Gelb BD, Tartaglia M (2007) LEOPARD syndrome. In: Pagon RA, Adam MP, Bird TD, Dolan CR, Fong CT, Stephens K (eds) GeneReviews™ [Internet]. University of Washington, Seattle, pp 1993–2013 3. Kalev I, Muru K, Teek R, Zordania R, Reimand T, Köbas K, Õunap K (2010) LEOPARD syndrome with recurrent PTPN11 mutation Y279C and different cutaneous manifestations: two case reports and a review of the literature. Eur J Pediatr 169:469–473 4. Keren B, Hadchouel A, Saba S, Sznajer Y, Bonneau D, Leheup B, Boute O, Gaillard D, Lacombe D, Layet V, Marlin S, Mortier G, Toutain A, Beylot C, Baumann C, Verloes A, Cavé H (2004) French Collaborative Noonan Study Group. PTPN11 mutations in patients with LEOPARD syndrome: a French multicentric experience. J Med Genet 41:e117 5. Kontaridis MI, Swanson KD, David FS, Barford D, Neel BG (2006) PTPN11 (Shp2) mutations in LEOPARD syndrome have dominant negative, not activating, effects. J Biol Chem 281:6785–6792 6. Kosaki K, Suzuki T, Muroya K, Hasegawa T, Sato S, Matsuo N, Kosaki R, Nagai T, Hasegawa Y, Ogata T (2002) PTPN11 (proteintyrosine phosphatase, nonreceptor-type 11) mutations in seven Japanese patients with Noonan syndrome. J Clin Endocrinol Metab 87:3529–3533 7. Martínez-Quintana E, Rodríguez-González F (2012) LEOPARD syndrome caused by Tyr279Cys mutation in the PTPN11 gene. Mol Syndromol 2:251–253 8. Sarkozy A, Conti E, Digilio MC, Marino B, Morini E, Pacileo G, Wilson M, Calabrò R, Pizzuti A, Dallapiccola B (2004) Clinical and molecular analysis of 30 patients with multiple lentigines LEOPARD syndrome. J Med Genet 41:e68 9. Sarkozy A, Digilio MC, Dallapiccola B (2008) Leopard syndrome. Orphanet J Rare Dis 3:13 10. Tartaglia M, Martinelli S, Stella L, Bocchinfuso G, Flex E, Cordeddu V, Zampino G, Burgt I, Palleschi A, Petrucci TC, Sorcini M, Schoch C, Foa R, Emanuel PD, Gelb BD (2006) Diversity and functional consequences of germline and somatic PTPN11 mutations in human disease. Am J Hum Genet 78:279–290 11. Voron DA, Hatfield HH, Kalkhoff RK (1976) Multiple lentigines syndrome. Case report and review of the literature. Am J Med 60:447–456 12. World Medical Association [homepage on the Internet]. Declaration of Helsinki—ethical principles for medical research involving human subjects [cited 2013 January 24]. Available from: http://www.wma. net/en/30publications/10policies/b3/index.html.pdf?print-mediatype&footer-right=[page]/[toPage]
