Causes Nemaline myopathy

In the majority of cases, a rod myopathy is inherited, although there are sometimes sporadic cases where there are no other family members affected. There have been mutations identified in five different genes, which cause rod myopathies. The protein products of all of these genes are involved in muscle tone and contraction.

ACTA1 – This gene produces a protein called α- actin. Mutations in this gene account for around 15 to 25 percent of cases. Errors in this gene are inherited in an autosomal dominant or autosomal recessive pattern.

NEM2 – The product of this gene is a protein called nebulin. It is thought that mutations in this gene are a common cause of nemaline myopathy but definite statistics are unavailable. Mutations in this gene are inherited in an autosomal recessive pattern.

TPM3 – The product of this gene is a protein called α- Tropomyosin 3. Mutations in this gene account for only two to three percent of affected individuals, and are inherited in an autosomal dominant or autosomal recessive pattern.

TPM2 – This gene encodes a protein called β-Tropomyosin. Only very few individuals have been identified with errors in this gene. Inheritance is in an autosomal dominant pattern.

TNNT1 – This gene produces a protein called Troponin 1. Errors in this gene have only been identified in a population of Old Order Amish individuals. Inheritance is in an autosomal recessive pattern.