Pyruvate carboxylase deficiency is a genetic issue where the body lacks a needed enzyme, causing a buildup of lactic acid and other substances in the blood.
This accumulation can harm the nervous system and organs, and there are three types of this condition.
Infantile Form (Type A): This type shows up in babies with delays in development, difficulty growing, weak muscles, and seizures. The excess lactic acid can lead to vomiting and breathing problems, especially after illness or not eating.
Severe Neonatal Form (Type B): This form appears soon after birth with low blood sugar, intense lactic acid buildup, a swollen liver, seizures, weak muscles, and odd movements.
Intermittent/Benign Form (Type C): This is the mildest type, where individuals may have normal or slightly delayed development and a bit more lactic acid. While there’s no cure, managing it involves a diet high in carbohydrates and protein, staying hydrated, and fixing biochemical issues with supplements. It’s important to avoid fasting and a high-fat, low-carb (ketogenic) diet as they can make symptoms worse.
Pyruvate carboxylase deficiency is caused by pathogenic (disease-causing) variants in the PC gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background.
Other names for this condition are ataxia with lactic acidosis, type II, Leigh necrotizing encephalopathy due to pyruvate carboxylase deficiency, and Leigh syndrome due to pyruvate carboxylase deficiency.
Resources:
National Organization for Rare Disorders
Revised November 2023
