Surveillance for immune/autoimmune dysfunction in Hereditary Sensory and Autonomic Neuropathy Type IV is suggested based on our findings.

Hereditary autonomic and sensory neuropathy (HSAN) type IV is due to mutations in Neurotrophic Tyrosine Receptor Kinase (NTRK1) gene. NTRK1 codes for a receptor that binds to Nerve Growth Factor, the latter being implicated in autoimmune disorders. HSAN type IV presents in infants as sensory dysfunction from a pathological lack of small myelinated and unmyelinated fibers and autonomic dysfunction due to lack of sweat gland innervation. Mental retardation, self-mutilating injuries from pain insensitivity and hyperpyrexia from defects in sweating are cardinal features of the disorder. 

We report a 2-year-old girl with HSAN type IV who presented with a novel complication of a mass compressing her cervical spine, along with abnormal blood counts that developed post a viral infection.

Additionally, we review all the cases of HSAN type IV reported so far providing corroborating evidence of immune dysfunction associated with the disease.

Our case: Laboratory results were evident for leukopenia and thrombocytopenia around the time of presentation. MRI cervical spine revealed a mass compressing C3-C7 requiring an urgent decompressive laminoplasty. Histopathological examination of mass was evident for chronic inflammatory cells.  

The development of an inflammatory mass post a viral infection, rapid decline of cell counts, biopsy findings of chronic inflammatory cells, with resolution post steroid administration suggested possible autoimmune phenomena in the disease.

We report HSAN type IV, in a patient of Acadian descent, the first report of the disorder in this population with a known prevalence of autosomal recessive disorders. Reports of humoral and innate immune dysfunction have been reported in HSAN IV but our case is the first report of autoimmune findings in the disorder. Screening for immune dysfunction in HSAN type IV will prevent fatal complications of the disease.