To explore phenotypic and mutational characteristics of a pedigree affected with autosomal dominant Charcot-Marie-Tooth disease (CMT) and nephropathy. Clinical data of the proband and his family members was collected. Electrophysiology, renal biopsy and next-generation sequencing were carried out for the proband. The proband presented with distal lower limb weakness and proteinuria in childhood. His mother and brother had similar symptoms. Electrophysiological test of the proband revealed demyelination and axonal changes in both motor and sensory nerves. Renal biopsy suggested focal segmental glomerulosclerosis. Genetic testing revealed a heterozygous c.341G>A (p.G114D) mutation in exon 2 of the INF2 gene. The phenotypic feature of the pedigree is autosomal dominant intermediate CMT and focal segmental glomerulosclerosis, which may be attributed to the c.341G>A mutation of the INF2 gene.

The Charcot-Marie-Tooth disease (CMT) is one of the most common human inherited peripheral neuropathies. The most common pattern of inheritance is autosomal dominant, with less often occurrence autosomal recessive and X-linked dominant/recessive inheritance. CMT is generally divided into three forms: demyelinating forms (CMT1), axonal forms (CMT2) and intermediate forms (DI-CMT). The autosomal recessive form (AR-CMT1 or CMT4) is accompanied by progressive distal muscle weakness and atrophy of the limbs, pes cavus and claw-like hands. In addition, CMT4 is also characterized by early onset, rapid progression, and varying degrees of sensory loss and spinal deformities (e.g. scoliosis). Recently, 11 subtypes of CMT4 have been identified. Some of these subtypes were clear in pathogenic mechanisms, some had founder mutation, but some still had limited clinical description and mutation analysis. In this review, we summarize the latest research progresses of CMT4, including genotypes and phenotypes, pathogenic mechanisms and mouse models.