About glutaric aciduria ii
What is glutaric aciduria ii?
Glutaricaciduria II is one of the conditions termed organic acidemias. Individuals with these conditions have a deficiency or absence of an enzyme that prevents them from breaking down certain chenicals in the body, resulting the accumulation of several organic acids in the blood and urine. Two enzymes that may be deficient in glutaricaciduria II are electron transfer flavoprotein (ETF) and ETF-ubiquinone oxidoreductase (ETF:QO). A complete enzyme deficiency causes a severe form of the disorder termed neonatal glutaricaciduria ll that is associated with a short life span and, sometimes, with specific physical birth defects. The less severe form of the disorder is termed late onset glutaricaciduria ll and has an extremely variable age of onset. Symptoms include nausea, vomiting, weakness and low blood sugar (hypoglycemia). Glutaricaciduria II is inherited as an autosomal recessive genetic disorder.
What are the symptoms for glutaric aciduria ii?
Signs and symptoms of GAII vary greatly depending on the age of onset and severity of the condition in each affected individual.
There are three main subtypes of GAII: the neonatal form with congenital anomalies, the neonatal form without congenital anomalies, and the late onset form. Newborns with the neonatal (first 4 weeks of life) form without conGenital anomalies may have severe hypoglycemia, respiratory distress, low muscle tone, an odor of sweaty feet, liver (hepatomegaly), heart (cardiomyopathy) and kidney abnormalities.
In addition to these symptoms, neonates having GAII with conGenital anomalies may also present with an abnormally Large head (macrocephaly), high forehead, flat nasal bridge, malformed ears, genital abnormalities, brain malformations, enlarged weak heart (cardiomyopathy), fluid-filled renal cysts, and unusual facial features. Complete enzyme deficiency found in severely affected patients with the neonatal form is not compatible with life beyond the first few days/weeks of life.
Symptoms present in patients with the late onset form of GAII generally appear in childhood to adulthood, are less severe and highly variable. Muscle Weakness is the most common symptom of this late onset form and individuals may have intermittent Vomiting and hypoglycemia. Some of these patients may respond very well to high dose oral riboflavin treatment.
What are the causes for glutaric aciduria ii?
Glutaric aciduria type II is an autosomal recessive disease caused by changes (mutations) in the ETF-A (subunit alpha), ETF-B (subunit beta) or ETFDH genes. The mutations result in deficient or complete absence of activity of multiple acyl-CoA dehydrogenase (MADD) enzymes needed to break down fats and proteins that the body uses for energy. This results in the accumulation of several organic acids in the blood and urine. Mutations in ETFA and ETFB generally cause the neonatal forms of this disorder and the ETFDH gene mutation is found in many late onset forms of GAII. Dysfunction of either ETF or ETFDH flavoproteins leads to compromised fatty acid oxidation and amino acid degradation that alters energy production as well as production of other molecules needed for fuel storage and use.
Recessive genetic disorders occur when an individual inherits a non-working gene from each parent. If an individual receives one working gene and one non-working gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk for two carrier parents to both pass the non-working gene and, therefore, have an affected child is 25% with each pregnancy. The risk to have a child who is a carrier, like the parents, is 50% with each pregnancy. The chance for a child to receive working genes from both parents is 25%. The risk is the same for males and females.
What are the treatments for glutaric aciduria ii?
The goal of treatment is to support development by regular monitoring & avoidance of acute life-threatening events through careful medical management & dietary control. However, children who have repeated metabolic crises may develop life-long learning & other health problems. Where necessary, treatment should be continued throughout life & this will apply to most patients.
What are the risk factors for glutaric aciduria ii?
Prevalence is estimated to be 1/200,000 and GAll affects both males and females. Prevalence in ethnicities is not known.
Is there a cure/medications for glutaric aciduria ii?
Glutaric aciduria type II is treated with a high carbohydrate, low protein and low fat diet. It is recommended that affected individuals eat often to avoid low blood sugar. Dietary supplementation with riboflavin, carnitine & other supplements may be helpful. It is important to have an emergency regimen ready & to alert the patient’s doctor if they should become ill, as illness can trigger a metabolic crisis.