SNP Shot: Genomic Insights

Distal hereditary motor neuropathy type V (dHMN V) is a condition that gradually worsens, impacting motor neurons within the spinal cord. This leads to muscle weakness and impaired movement, primarily affecting the hands and feet.

The symptoms of dHMN V typically manifest during the teenage years, although the age of onset can range from infancy to around 35 years old. Often, the first noticeable sign is hand cramping triggered by cold exposure.

Key characteristics of dHMN V include muscle weakness and atrophy, particularly in the hand muscles associated with the thumb, specifically the thumb side of the index finger, and the palm at the base of the thumb. Foot deformities, such as pes cavus (high-arched foot), are frequently observed. Some individuals with dHMN V will eventually develop walking difficulties (gait abnormalities). Importantly, this condition does not affect life expectancy.

Inheritance:

dHMN V follows an autosomal dominant inheritance pattern. This means that only one copy of the mutated gene in each cell is needed to cause the disorder. However, some individuals carrying the mutated gene may not exhibit any symptoms of the condition; this is referred to as reduced penetrance.