SNP Shot: Genomic Insights

Rippling muscle disease is characterized by heightened muscle sensitivity (irritability) to movement or pressure. This condition primarily affects muscles closer to the body's core, particularly those in the thighs. A hallmark sign is visible ripples spreading across the muscle surface upon stretching, typically lasting 5 to 20 seconds. Additionally, a sudden impact on the muscle can trigger it to bunch up (percussion-induced muscle mounding) or undergo rapid, repetitive tensing (percussion-induced rapid contraction). These contractions can persist for up to 30 seconds and may be accompanied by pain.

Individuals with rippling muscle disease may exhibit muscle overgrowth (hypertrophy), most notably in the calf muscles. Some may also display an unusual walking pattern (gait), such as toe-walking. Other symptoms can include fatigue, muscle cramps, or stiffness, especially following physical activity or exposure to cold temperatures.

The onset of rippling muscle disease varies, often starting in late childhood or adolescence. Notably, rippling muscles can also be a symptom of other muscle disorders like limb-girdle muscular dystrophy.

Inheritance:

Rippling muscle disease is commonly inherited in an autosomal dominant manner, but occasionally follows an autosomal recessive inheritance pattern. Autosomal dominant inheritance means that only one altered copy of the CAV3 gene in each cell is enough to cause the condition. In most instances, an affected individual has a parent with rippling muscle disease or another related condition (caveolinopathy). Infrequently, the condition arises from new gene mutations in individuals with no family history of caveolinopathies. Autosomal recessive inheritance requires mutations in both copies of the CAV3 gene in each cell. In this scenario, each parent carries one copy of the mutated gene, but they usually don't exhibit any signs or symptoms of the condition. Individuals with autosomal recessive rippling muscle disease generally experience more severe symptoms compared to those with the autosomal dominant form.