Table of Contents
Glutaric aciduria is an inherited metabolic disorder that involves the body being unable to process different proteins. Those with this disorder have inefficient levels of an enzyme that breaks down the amino acids tryptophan, hydroxylysine and lysine. These amino acids are the building blocks of protein and extreme levels in the body can accumulate and cause brain damage.
Glutaric aciduria can cause damage to the basal ganglia in the brain and it may result in intellectual disabilities. The severity of the disorder can vary widely, some people are only moderately affected and others will have profound problems. In most situations, signs and symptoms will show up during infancy or early childhood. However, in a small number of people, it first becomes apparent during adolescence or adulthood.
Different Types Of Glutaric Aciduria
There are three different types of glutaric aciduria, and each one has its own unique symptoms.
- The first thing most will notice with GA-1 is a baby having microencephalic macrocephaly (small brain in a large head)
- Failing to thrive, poor muscle development and low blood sugar
- It may cause brain damage in the basal ganglia
- Gastroesophageal problems
- Skeletal issues
- Respiratory complications
- Cerebral palsy
- Cardiac failure
- Respiratory distress
- Musty breath (often described as smelling like sweaty feet)
- Muscle hypotonia
- Liver damage
- Renal and/or cardiac problems
- Proximal myopathy (weakness)
- Chromosomal abnormalities
- Bowel disorders
- Thyroid dysfunction
- Failure to thrive
How Rare Is Gluratic Aciduria?
Type I glutaric aciduria is extremely rare. There have been limited studies of the disorder that suggest it occurs in one in 40,000 Caucasian births. However, a study in Sweden estimated the incidence of the disorder around one in 30,000 births in its population. It’s more common in genetically close cultures such as the Ojibway Indian population in Canada or in the Amish in the United States, where it can happen as much as 1 in 300 births. There is a tendency to misdiagnose this disorder, which makes it difficult to get an accurate figure of the frequency.
How Is Glutaric Aciduria Diagnosed?
Glutaric aciduria Type 1 is a rare disease that may lead to acute brain damage in early childhood. The brain damage it causes can result in a severe dystonic disorder which is very similar to cerebral palsy. Diagnosing the disease will be dependent upon the recognition of relatively non-specific physical findings. A doctor may order a blood or urine test to check a person’s levels of glutarylcarnitine, which if high, would be an indication of the disease.
Test Results: Positive Or Negative?
If a person is tested for glutaric aciduria and a gene mutation is identified, it’s important to speak to a physician or genetic specialist about the implications. A negative test result will reduce, but not eliminate, the likelihood of an individual carrying a genetic mutation. The chances of a person being a carrier of the gene will be influenced by family history, medical symptoms and other relevant test results.
Can It Be Prevented?
It’s entirely possible to screen a newborn baby for Type I glutaric aciduria using blood from a heel-prick test and running it through a tandem-mass-spectrometer. The technique is being used in high risk populations like the Amish. Using this method of testing can help to minimize the amount of brain damage the disease causes, by early dietary manipulation and supplements. Because this disease is so uncommon, routine population-based testing is not currently used.