[Clinical and genetic analysis of a patient with Perrault syndrome and additional neurological features].

Objective: To explore the clinical, neuropathological and genetic characteristics of a patient with Perrault syndrome caused by TWNK mutation.

Methods: Potential variation of the TWNK gene was detected by next-generation sequencing (NGS) and verified by Sanger sequencing.

Results: The patient has featured primary amenorrhoea and progressive sensorineural hearing loss since childhood. She also had gait anormaly, distal limb atrophy and weakness, and nystagmus. Further study confirmed sensory neuronopathy accompanied with upper and lower motor neuron involvement as well as cerebellum atrophy. NGS has identified two heterozygous variants of the TWNK gene, namely c.794G>A (p.Arg265His) and c.1181G>A (p.Arg394His). Sanger sequencing confirmed that c.1181G>A (p.Arg394His), a known pathogenic variant, was derived from her farther, while c.794G>A(p.Arg265His), a novel variant, was derived from her mother and likely pathogenic according to the ACMG guidelines.

Conclusion: Perrault syndrome is a group of disorders with a high phenotypic heterogeneity. The compound heterozygous variation of c.794G>A (p.Arg265His) and c.1181G>A(p.Arg394His) of the TWNK gene may underlie Perrault syndrome in the patient.