Co-occurrence of an HSPG2 Missense Variant and Functional Polymorphisms in Atypical Schwartz–Jampel Syndrome Type 1 with Obesity: A Case Report
27 March 2018
06 July 2018
15 August 2018 (eFirst)
Schwartz–Jampel syndrome type 1 (SJS1) is an autosomal recessive chondrodystrophic myotonia, linked to heparan sulfate proteoglycan 2 (HSPG2) variants. We describe a patient with typical features of SJS1, but not obesity. Clinical exome sequencing detected a rare missense variant in HSPG2, confirming our clinical diagnosis, but also two homozygous variants in SDC3 and ADRB3 genes, previously described to be associated with obesity. This additional genetic result could better explain our patient's phenotype. Despite the phenotypic variability associated to HSPG2 variants, it is advisable to carefully check other possible genetic causes underlying clinical signs not strictly related to the classical phenotype of SJS1.
Statement of Ethics
Informed consent was obtained from the patient's parents following a full explanation of the procedures undertaken. Written consent for publication of photographs and all other clinical details were obtained.
* These authors equally contributed to this work.
- 1 Basiri K, Fatehi F, Katirji B. The Schwartz-Jampel syndrome: case report and review of literature. Adv Biomed Res 2015; 4: 163
- 2 Yang MT, Yang CC, Chu LW, Lee WT, Young C, Wang PJ. Schwartz-Jampel syndrome: report of one case. Acta Paediatr Taiwan 2002; 43 (04) 220-223
- 3 Nicole S, Davoine CS, Topaloglu H. , et al. Perlecan, the major proteoglycan of basement membranes, is altered in patients with Schwartz-Jampel syndrome (chondrodystrophic myotonia). Nat Genet 2000; 26 (04) 480-483
- 4 Iwata S, Ito M, Nakata T. , et al. A missense mutation in domain III in HSPG2 in Schwartz-Jampel syndrome compromises secretion of perlecan into the extracellular space. Neuromuscul Disord 2015; 25 (08) 667-671
- 5 Stum M, Davoine CS, Vicart S. , et al. Spectrum of HSPG2 (Perlecan) mutations in patients with Schwartz-Jampel syndrome. Hum Mutat 2006; 27 (11) 1082-1091
- 6 Das Bhowmik A, Dalal A, Matta D, Kandadai RM, Kanikannan MA, Aggarwal S. Identification of a novel splice site HSPG2 mutation and prenatal diagnosis in Schwartz Jampel Syndrome type 1 using whole exome sequencing. Neuromuscul Disord 2016; 26 (11) 809-814
- 7 Schüring AN, Lutz F, Tüttelmann F, Gromoll J, Kiesel L, Götte M. Role of syndecan-3 polymorphisms in obesity and female hyperandrogenism. J Mol Med (Berl) 2009; 87 (12) 1241-1250
- 8 Daghestani M, Daghestani M, Daghistani M. , et al. ADRB3 polymorphism rs4994 (Trp64Arg) associates significantly with bodyweight elevation and dyslipidaemias in Saudis but not rs1801253 (Arg389Gly) polymorphism in ARDB1. Lipids Health Dis 2018; 17 (01) 58
- 9 Arya R, Sharma S, Gupta N, Kumar S, Kabra M, Gulati S. Schwartz Jampel syndrome in children. J Clin Neurosci 2013; 20 (02) 313-317
- 10 Samimi SS, Lesley WS. Craniocervical CT and MR imaging of Schwartz-Jampel syndrome. AJNR Am J Neuroradiol 2003; 24 (08) 1694-1696