SNP Shot: Genomic Insights

Amish lethal microcephaly is a condition characterized by newborns having a significantly smaller head and an underdeveloped brain.

Babies with Amish lethal microcephaly typically present with a receding forehead and a dramatically reduced head circumference. Additionally, they might have an undersized lower jaw and chin (micrognathia) along with an enlarged liver (hepatomegaly).

Infants affected by this disorder may experience seizures and struggle to regulate their body temperature. They often exhibit increased irritability beginning around two to three months of age. The presence of alpha-ketoglutaric acid can be detected in their urine (alpha-ketoglutaric aciduria). Furthermore, during viral infections, they are prone to developing elevated acid levels in their blood and tissues (metabolic acidosis). While feeding is usually adequate, these infants do not acquire developmental milestones such as intentional movement or the ability to visually and auditorily track faces and sounds. Unfortunately, infants with this condition typically survive for only approximately six months.

Inheritance:

The inheritance pattern of this condition is autosomal recessive. This means that both copies of the responsible gene within each cell must possess mutations for the disorder to manifest. Individuals carrying only one copy of the mutated gene, known as carriers, are usually unaffected and do not display symptoms of the condition. The parents of a child with an autosomal recessive condition are both carriers.