merosinipuutos

Merosinipuutos is a rare genetic disorder that affects muscle development. It is caused by mutations in the LAMA2 gene, which provides instructions for making an alpha-2 subunit of laminin. Laminin is a protein found in the extracellular matrix, a network of molecules outside of cells that provides structural support and helps cells bind to each other. In muscles, laminin plays a crucial role in anchoring muscle fibers to the surrounding tissue.

When the LAMA2 gene is mutated, the alpha-2 subunit of laminin is either absent or non-functional. This leads to a severe deficiency of laminin-211, a specific form of laminin essential for muscle integrity. As a result, muscle fibers become fragile and prone to damage. This damage can occur during normal muscle activity, leading to progressive muscle weakness and degeneration.

The symptoms of merosinipuutos typically appear at birth or in early infancy. Affected individuals often exhibit severe muscle weakness, known as hypotonia, and have difficulty with motor skills such as lifting their head, sitting, and crawling. While some may be able to walk with assistance, many remain unable to walk independently. Respiratory muscles can also be affected, potentially leading to breathing difficulties. The intellectual development of individuals with merosinipuutos is usually normal.

There is currently no cure for merosinipuutos. Treatment focuses on managing symptoms and improving quality of life. This may include physical therapy to maintain muscle function and range of motion, respiratory support if needed, and management of feeding difficulties. Prognosis varies, with the severity of muscle weakness and respiratory involvement being key factors.