A Rare Case of Charcot-Mari-Tooth Disease Type 2S in a 20-year-old Man

Abstract

Charcot-Marie-Tooth disease type 2 (CMT2S) is rare form of Charcot-Marie-Tooth disease (CMT) that is characterized by a mutation in the IGHMBP2 gene. This gene encodes a helicase superfamily member that binds a specific DNA sequence from the region of the immunoglobulin mu chain switch. Mutation of this gene leads to spinal muscle atrophy with respiratory distress type 1 and CMT2S. This case report presents a 20-year-old male with genetically confirmed CMT2S having clinical respiratory involvement and symmetrically involved lower extremities. DNA sequencing revealed a previously unknown heterozygous mutation in the exone 2 of the IGHMBP2 gene leading to the replacement of the amino acid in the 46 position of the protein (chr11q13.3: 68673587 G>C). These atypical features widen the clinical spectrum of CMT2S. In describing this clinical case, we also improve diagnostic management and try to increase the alertness of various doctors towards neuromuscular diseases, including CMT.

Keywords

• Charcot-Marie-Tooth disease
• Inherited Axonal Predominant Neuropathy
• Neuromuscular Disease
• Chomosome11q13.3