Charcot-Marie-Tooth disease type 2S (CMT2S) is a rare form of inherited peripheral neuropathy that affects both motor and sensory nerves. The disease is caused by mutations in the IGHMBP2 gene, which encodes a protein involved in the maintenance and function of motor neurons.
A missense mutation is a type of genetic mutation that results in a single amino acid change in the protein encoded by the affected gene. In the case of CMT2S, a missense mutation in the IGHMBP2 gene leads to the production of a faulty protein that cannot perform its normal functions in the cell.
The fact that the same missense mutation was identified in two unrelated families with CMT2S suggests that it is a pathogenic mutation that is responsible for the disease phenotype in these individuals. The mutation is likely to have occurred independently in both families, rather than being inherited from a common ancestor.
Identifying the specific genetic mutation responsible for CMT2S is important for the diagnosis and genetic counseling of affected individuals and their families. It also provides insights into the underlying mechanisms of the disease and may lead to the development of targeted therapies in the future.