ATL3 gene mutation in a Chinese family with hereditary sensory neuropathy type 1F.

Hereditary sensory neuropathy (HSN) comprises a group of progressive peripheral neuropathies predominantly affecting the sensory nerves. To date, two different ATL3 gene mutations have been reported to be responsible for HSN type 1F (HSN1F). Here, we report a family in which the members presented numbness of the lower limbs and recurrent foot ulceration. Symptoms of foot ulcers disappeared in the years after onset, which suggests that the family members showed benign and mild symptoms compared with the affected patients reported previously. Laboratory examinations and electrophysiological data suggested axonal degeneration of the peripheral sensory nerves, while motor neurons were not involved. Exome sequencing revealed the previously reported c.C1013G (p.Pro338Arg) mutation of the ATL3 gene. This is the first report of ATL3 mutation in Chinese patients with HSN. Cells expressing mutant ATL3 exhibited disruption of the endoplasmic reticulum network, suggesting a dominant-negative effect. There was no significant difference in the expression of the endoplasmic reticulum stress marker binding immunoglobulin protein (BiP) between cells expressing wild-type or mutant ATL3. Further studies are required to ascertain the relevance of the changes in endoplasmic reticulum morphology to axonal degeneration of sensory nerves.