Ullrich Congenital Muscular Dystrophy (UCMD) is a rare genetic disorder that primarily affects the muscles and connective tissues. It is classified as a subtype of congenital muscular dystrophy, a group of inherited muscle disorders characterized by muscle weakness and wasting.
The exact cause of UCMD is attributed to mutations in specific genes that are involved in the production of collagen, a protein that provides structure and support to various tissues in the body. UCMD is primarily caused by mutations in the COL6A1, COL6A2, and COL6A3 genes, which are responsible for producing the collagen VI protein.
Collagen VI is a crucial component of the extracellular matrix, a network of proteins and other molecules that surrounds and supports cells. It plays a vital role in maintaining the integrity and function of muscles and connective tissues. Mutations in the COL6A1, COL6A2, and COL6A3 genes lead to the production of abnormal collagen VI or reduce its production, resulting in the characteristic features of UCMD.
UCMD is inherited in an autosomal recessive manner, meaning that an affected individual must inherit two copies of the mutated gene (one from each parent) to develop the condition. If both parents carry a single copy of the mutated gene, they are considered carriers and have a 25% chance of having an affected child with each pregnancy.
The symptoms of UCMD typically manifest in early childhood. Infants with UCMD may have weak muscle tone (hypotonia) and difficulty with motor skills such as crawling, sitting, and walking. They may also experience joint stiffness and contractures, which limit their range of motion. As the disease progresses, muscle weakness and wasting become more pronounced, leading to significant mobility issues and respiratory complications.
While the genetic mutations responsible for UCMD have been identified, the exact mechanisms by which they lead to the specific symptoms and progression of the disease are still being studied. Researchers are actively investigating the role of collagen VI in muscle and connective tissue development to gain a better understanding of UCMD and potentially develop targeted therapies.