SNP Shot: Genomic Insights

Hypermethioninemia refers to a condition where there's too much methionine, an amino acid vital for building proteins, in the bloodstream. This buildup happens when the body struggles to properly process (metabolize) methionine.

Many individuals with hypermethioninemia experience no noticeable symptoms. However, some may exhibit intellectual disability, neurological issues, delayed motor development (like standing or walking), lethargy, muscle weakness, liver dysfunction, distinct facial characteristics, and a boiled cabbage-like odor in their breath, sweat, or urine.

Hypermethioninemia can arise alongside other metabolic disorders like homocystinuria, tyrosinemia, and galactosemia, all of which involve problems in breaking down specific molecules. It can also stem from liver ailments or consuming excessive amounts of methionine through a high-protein diet or methionine-fortified baby formula. When hypermethioninemia isn't linked to other metabolic disorders or high methionine intake, it's classified as primary hypermethioninemia.

Inheritance:

Hypermethioninemia's inheritance can vary. Typically, it follows an autosomal recessive inheritance pattern, meaning that both copies of the responsible gene in each cell must have changes (variants) for the condition to manifest. Often, the parents of someone with an autosomal recessive condition each carry one copy of the altered gene, but they don't display symptoms themselves. Occasionally, hypermethioninemia is inherited in an autosomal dominant pattern. In this case, only one copy of the altered gene in each cell is enough to cause the disorder. Usually, a person affected by the dominant form has one parent who also has the condition.