Clinical and genetic features of Schwartz-Jampel syndrome in a Chinese child: case report and literature review / 中华儿科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the clinical and genetic features of a Chinese girl with Schwartz-Jampel syndrome (SJS).</p><p><b>METHOD</b>To analyze the clinical and genetic data of a girl with Schwartz-Jampel syndrome who was sent to neurology outpatient department of Beijing Children's Hospital in Auguest of 2010. Reports on Schwartz-Jampel syndrome published until July of 2015 were searched and the clinical and genetic characteristics of reported cases were summarized.</p><p><b>RESULT</b>At 8 months after birth, the girl showed myotonia; at 1 year old when she was walking alone she had myotonia of lower limbs, both feet evaginated, walked slowly and was prone to fall. At 2 years of age, she could not climb up stairs, at 3 years she could not jump continuously. At 3 years and 7 months of age when the girl was taken to neurology outpatient department, on examination, she had a dull facial expression, rigid lips and could not fully open her mouth, a micromandible, low-set and prominent ears, systemic muscle rigidity, there were muscular nodes formation on the limbs and gait stiffness. She had high level of creatine kinase and atlanto-axial joint subluxation on cervical CT reconstruction. She also had spontaneous myotonia-like discharges on needle electromyography (NEMG). X-ray of limbs showed metaphyseal dysplasia. The patient was treated with neurologic rehabilitation and carbamazepine. The myotonia at the last follow-up at her 8 years of age was the same as at the onset. On her HSPG2 gene, two novel heterozygous mutations c.10776delT on exon 78 and c.5702-5G>A on intron 45 were found. c.10776delT resulted in the amino acid change on p.Ala3592fsX6 and c.5702-5G>A maybe changed protein splicing. No reports were found among Chinese journals, while 7 reports were found in English literature. The total 34 mutations were known in reviewed reports, which included eleven deletion or insertion, twelve splice site, eight missense, and three nonsense mutations. Four patients had a single mutation. No definite genotype-phenotype correlation was identified.</p><p><b>CONCLUSION</b>Schwartz-Jampel syndrome is a rare autosomal-recessive hereditary disease appears to be slowly progressive, in which distinctive clinical features were induced by HSPG2 gene mutation. We reported the c.10776delT on exon 78 and c.5702-5G>A on intron 45 which were not reported previously. This is the first report of Schwartz-Jampel syndrome of which genetic mutations was identified in a Chinese child.</p>