Spectrum of SPTLC1-related disorders: a novel case of 'Ser331 syndrome' that expand the phenotype of hereditary sensory and autonomic neuropathy type 1A and motor neuron diseases

We report a patient with early-onset hereditary sensory and autonomic neuropathy type 1A (HSAN-1A) who developed a distinct phenotype, with tongue fasciculation and atrophy, due to a mutation at serine 331 in the SPTLC1 gene. HSAN-1A manifestation causing tongue fasciculation and atrophy have been rarely found. Our report adds to the growing evidence of the existence of an overlap between hereditary neuropathy and motor neuron disease caused by pathogenic p.S331Y variant in SPTLC1 gene.

Automated summary

We present a case of early-onset hereditary sensory and autonomic neuropathy type 1A (HSAN-1A) with a unique phenotype of tongue fasciculation and atrophy, caused by a mutation at serine 331 in the SPTLC1 gene. The manifestation of tongue fasciculation and atrophy in HSAN-1A is rarely reported. Our findings contribute to the increasing evidence of an overlap between hereditary neuropathy and motor neuron disease caused by the pathogenic p.S331Y variant in the SPTLC1 gene.