Abstract
Mutations in the Berardinelli-Seip congenital lipodystrophy 2 (BSCL2) gene are rare and present with variety of clinical phenotypes. This report will describe a case of a BSCL2 variant syndrome causing a CMT2 phenotype. A 16-year-old male presented to a neurology outpatient clinic with two years of worsening hand weakness causing difficulty with fine motor tasks. There had been a childhood history of gait disturbance that progressed in early teenage years to an inability to run. There was no family history of neurological disease. Physical examination showed weakness and wasting distally in all four limbs with reflexes present. Initial investigations showed a creatine kinase of approximately 400 and a myopathy gene panel was negative. Subsequent nerve conduction studies showed electrophysiological evidence of a motor neuropathy in the upper and lower limbs. The sensory responses were normal. A hereditary neuropathy gene panel showed BSCL2 gene pathogenic variant c.269C>T p.Ser90Leu. BSCL2 variants, seipinopathies, have a motor dominant neuropathy where sensory involvement can be absent or mild. Inheritance is in an autosomal dominant fashion where there can be incomplete penetrance and the incidence of de novo mutations is unknown. The pertinent point is that this pathogenic variant is rare and has a wide clinical phenotype that is not typical of other CMT types and can cause a distal hereditary motor neuropathy.
