SNP Shot: Genomic Insights

Tibial muscular dystrophy is a disorder impacting the muscles in the front of the lower leg. Symptoms usually start after age 35. The initial sign is often weakness and muscle loss (atrophy) in the tibialis anterior, a lower leg muscle. This muscle is vital for foot movement, specifically moving it up and down. When the tibialis anterior weakens, walking on the heels becomes challenging or impossible, although it generally doesn't greatly affect normal walking ability.

In tibial muscular dystrophy, muscle weakness progresses very slowly. After 10 to 20 years, weakness may develop in the muscles that extend the toes (long-toe extensors). This leads to difficulty lifting the toes while walking, a condition called foot drop. Later in life, about a third of individuals with this condition may experience mild to moderate walking difficulties due to weakness in other leg muscles. However, the majority of those affected retain the ability to walk throughout their lives.

A small number of people with tibial muscular dystrophy exhibit a slightly different symptom pattern. They may develop generalized muscle weakness starting in childhood, along with weakness and atrophy in the thigh muscles (quadriceps) or other leg muscles, and sometimes weakness in the arm muscles as well.

Inheritance:

The inheritance pattern is autosomal dominant. This means that only one copy of the mutated gene in each cell is enough to cause the disorder.