MYH3 gene

The MYH3 gene is responsible for producing myosin-3, a protein critical for fetal muscle development, with variants leading to specific skeletal and muscle disorders.

Overview

The MYH3 gene provides instructions for making myosin-3, a protein involved in movement and the transport of materials within cells. Myosin-3 is a primary component of thick filaments in muscle fibers, which work alongside actin to facilitate muscle contraction. This specific type of myosin is found primarily in the fetus before birth and is essential for early muscle development.

Health Conditions Related to Genetic Changes

Freeman-Sheldon syndrome

Variants in the MYH3 gene cause Freeman-Sheldon syndrome, a disorder affecting muscle and skeletal development. It is characterized by contractures—the permanent tightening of muscles, skin, and tissues—which restrict movement and cause distinctive facial features and deformities of the hands and feet. Researchers believe these variants may cause myosin to attach to actin for too long, preventing muscle relaxation and leading to the stiffening of tissues during development.

Sheldon-Hall syndrome

Variants in the MYH3 gene can also cause Sheldon-Hall syndrome, which is similar to but milder than Freeman-Sheldon syndrome. These variants are believed to interfere with the ability of myosin-3 to attach to actin and other proteins, impairing muscle contraction and development before birth.

Spondylocarpotarsal synostosis syndrome

The MYH3 gene has also been linked to spondylocarpotarsal synostosis syndrome, a condition involving abnormal bone fusion and skeletal development.

Genomic Location

The MYH3 gene is found on chromosome 17.