Myosin Heavy Chain 8, Skeletal Muscle, Perinatal (MYH8)

Muscle myosins are heterohexamers composed of 2 myosin heavy chains and 2 pairs of nonidentical myosin light chains. This gene encodes a member of the class II or conventional myosin heavy chains, and functions in skeletal muscle contraction. MYH8 is predominantly expressed in fetal skeletal muscle. This gene is found in a cluster of myosin heavy chain genes on chromosome 17. A mutation in this gene results in trismus-pseudocamptodactyly syndrome.In 18 affected members of the family, they identified a 2094G-A transition in exon 16 of the MYH8 gene, resulting in an arg674-to-gln (R674Q) substitution. The arginine residue at position 674 is highly conserved evolutionarily, localizes to the actin-binding domain of the perinatal myosin head, and is close to the ATP-binding site.