The hereditary sensory and autonomic neuropathies (HSAN) are rare inherited neuropathies presenting with sensory loss and complications, including ulcers, infections, osteomyelitis and amputations. Usually, sensory symptoms predominate although motor involvement can occur. Autonomic features may be minimal (then hereditary sensory neuropathy, HSN, is preferred). HSAN has been classified into five subtypes depending on clinical presentation.
Hereditary sensory and autonomic neuropathy II (HSANII or HSNII) is an early onset, autosomal recessive sensory neuropathy with ulcero-mutilating complications due to mutations in the HSN2 isoform of the WNK1 gene. Recently, a similar phenotype was described in a Saudi-Arabian family, and a homozygous nonsense mutation found in a new gene, FAM134B (family with sequence similarity 134, member B), encoding a newly identified Golgi protein. The index case in this family was initially thought to have leprosy. Three additional families (out of 75 patients) with similar phenotypes were found to have homozygous loss of function mutations in FAM134B.
Here, we report the clinical and pathological findings in a further patient with HSNII due to a homozygous mutation in FAM134B.