SNP Shot: Genomic Insights

Pyruvate carboxylase deficiency is a genetic condition where harmful substances, including lactic acid, build up in the blood. This buildup can harm organs and tissues, especially the nervous system.

There are at least three types of pyruvate carboxylase deficiency, classified by the severity of their symptoms. Type A, primarily seen in North America, is severe and begins in infancy. Symptoms include developmental delays and lactic acidosis (high lactic acid in the blood). Lactic acidosis can cause vomiting, abdominal pain, fatigue, muscle weakness, and breathing problems. Illness or fasting can sometimes trigger these episodes. Infants with type A often only live until infancy or early childhood.

Type B pyruvate carboxylase deficiency presents with life-threatening symptoms soon after birth. It's more common in Europe, particularly France. Infants with type B experience severe lactic acidosis, hyperammonemia (high ammonia in the blood), and liver failure. They also have neurological problems like hypotonia (weak muscle tone), abnormal movements, seizures, and coma. These infants typically survive less than 3 months.

A less severe form, sometimes called type C, also exists. Type C is characterized by slightly elevated lactic acid levels and few or no nervous system symptoms.

Inheritance:

The condition follows an autosomal recessive inheritance pattern. This means a person must inherit a mutated copy of the gene from both parents to have the condition. The parents, who each carry one copy of the mutated gene, usually don't show symptoms themselves.