SNP Shot: Genomic Insights

Hypomyelination and congenital cataract is a genetic disorder passed down through families, impacting both the nervous system and the eyes. It belongs to a category of genetic conditions known as leukoencephalopathies, which are characterized by abnormalities in the brain's white matter. White matter is composed of nerve fibers coated with myelin, a fatty substance crucial for insulating these fibers and ensuring swift nerve impulse transmission. This specific condition arises from impaired myelin production (hypomyelination). Furthermore, individuals affected by this disorder are typically born with cataracts, a clouding of the lens in both eyes.

Infants with hypomyelination and congenital cataract generally exhibit normal development during their first year. However, development slows down around age 1. Most affected children learn to walk between 1 and 2 years old, though they often require support. Over time, they develop muscle weakness and atrophy in their legs, leading many to need wheelchairs. Some individuals experience trunk muscle weakness and progressive scoliosis, further hindering their ability to walk. Peripheral neuropathy, characterized by reduced sensation in the arms and legs, is common. Affected individuals also often exhibit speech difficulties (dysarthria) and mild to moderate intellectual disability.

Inheritance:

The inheritance pattern for this condition is autosomal recessive. This means that for a person to be affected, they must inherit a mutated copy of the responsible gene from both parents. The parents, who each carry only one copy of the mutated gene, are usually unaffected and do not display symptoms of the condition.