Glutaric acidemias are a group of disorders where a substance called glutaric acid builds up in urine. One type, known as glutamic acidemia type 1 (GA I), is a genetic condition where the body lacks an enzyme to break down certain amino acids properly.
This buildup of amino acids can damage the brain, affecting movement and thinking abilities. The severity of symptoms varies greatly. Some people show no signs, while others experience significant movement issues or intellectual disabilities. In babies with GA I, an enlarged head is a common sign, but it’s not exclusive to this condition. Additional symptoms often appear between 6 and 18 months, usually after an illness. Glutaric acid buildup can cause a loss of motor skills, although intelligence is often unaffected. During a “metabolic crisis,” children might experience low blood sugar, vomiting, lack of energy, and poor muscle tone. If not treated promptly, this can lead to serious complications, including brain damage and even death. Some children with GA I may have bleeding in the brain or eyes, which has been mistaken for abuse. Early diagnosis and a carefully controlled diet can prevent these crises and reduce the risk of brain damage. Specialized treatment plans, including low-protein diets and supplements, are designed with the help of metabolic specialists. When a child is sick, specific plans are in place to manage symptoms and prevent crises. Physical and occupational therapy can also be beneficial in managing the condition and improving quality of life.
GA1 I is caused by pathogenic (disease-causing) variants in the GCDH 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 glutaric aciduria I and glutaryl-CoA dehydrogenase deficiency.