A novel homozygous nonsense mutation in NEFL causes autosomal recessive Charcot-Marie-Tooth disease

Abstract

The neurofilament light polypeptide (NEFL) gene mutations cause mainly autosomal dominant Charcot-Marie-Tooth disease (CMT) and rarely the recessive forms of CMT. We describe a 13-year-old girl born of consanguineous parents. She presented an early onset of gait disturbance with weakness in lower extremities during the first decade. Nerve conduction velocity of median nerve was 24 m/s and amplitude of compound muscle action potential was 2.2 mV. Sensory nerve action potential was not recordable. Sural nerve biopsy showed severe loss of the large myelinated fibers. Electron microscopy revealed absence of neurofilaments in both myelinated and unmyelinated axons. Genetic analysis identified a novel homozygous nonsense mutation in NEFL c.487G>T (p.Glu163*) as the potential causative mutation in this patient. Our study expands the mutation spectrum of NEFL-related neuropathy.

Keywords: Autosomal recessive; Charcot–Marie–Tooth disease; Homozygous mutation; NEFL.