Novel Compound Heterozygous DST Variants Causing Hereditary Sensory and Autonomic Neuropathies VI in Twins of a Chinese Family

Abstract

Background: Hereditary sensory and autonomic neuropathies (HSANs) are a rare and severe group of sensory axonal neuropathies. HSANs have been classified into eight groups based on mode of inheritance, clinical features, and the involved genes. HSAN-VI, perhaps the most notable type, is an autosomal recessive disease, which manifests as the severely impaired pain sensitivity, autonomic disturbances, distal myopathy, spontaneous or surgical amputations, and sometimes early death. Mutations in DST have been identified as the cause of HSAN-VI. DST encodes dystonin, a member of the plakin protein family that is involved in cytoskeletal filament networks. Dystonin has seven major isoforms in nerve, muscle, and epithelium. Material and Methods: The present study investigated a Chinese family with HSAN and explored potential pathogenic variants using whole-exome sequencing (WES). Variants were screened and filtered through bioinformatics analysis and prediction of variant pathogenicity. Co-segregation analysis was subsequently conducted. Results: We identified compound heterozygous variants of DST (c.3304G>A, p.V1102I and c.13796G>A, p.R4599H) in two patients. Conclusion: We reported on a Chinese family with HSAN-VI family and detected the disease-causing variants. Our description expands the spectrum of known DST variants and contributes to the clinical diagnosis of HSAN-VI.