MCKAT deficiency is inherited in an autosomal recessive pattern. Normally a person has two functional genes. In people with MCKAT deficiency, both genes have a mutation and there is a deficiency of the critical enzyme activity. Each parent of a newborn with MCKAT deficiency typically has one functional and one mutated gene and is considered a carrier. When both parents are carriers, the chance of a newborn inheriting two mutated genes is 25%.
There has only been one report of a patient with MCKAT deficiency. It is unknown if carriers would have any symptoms.
The single known baby with MCKAT deficiency died at 13 days of age and had low blood sugar, elevated ammonia, vomiting, dehydration and myoglobinuria (myoglobin in the urine due to muscle breakdown).
- Incidence: MCKAT deficiency is extremely rare. The overall incidence is unknown.
- New York State Method of Screening (First Tier): Screening for MCKAT deficiency is accomplished by measuring an acylcarnitine (C8) by tandem mass spectrometry (MS/MS).
- Second Tier Screening: None
- Testing can be affected by: None known due to lack of information available about this disorder. Newborn screening cannot distinguish among MCAD deficiency, MAD deficiency and MCKAT deficiency; however, MCKAT deficiency and MAD deficiency are rarer than MCAD deficiency.
- Interpretation/reporting of data: Results are reported as within acceptable limits, borderline or as a referral. A repeat specimen should be collected for a borderline result. Prompt consultation with a specialist is required for a referral.
- Referral to Specialty Care Center: Patients with an abnormal newborn screen for MCKAT deficiency are referred to an Inherited Metabolic Disorder Specialty Care Center for evaluation by a biochemical geneticist trained in the diagnosis and treatment of MCKAT deficiency.
Diagnostic testing may include quantification of plasma acylcarnitines and fatty acid oxidation studies on fibroblasts (skin cells).
No treatment information available due to rarity of the disorder.
Prognosis is unknown. Outcome was poor in the single patient reported.
Medium-chain 3-ketoacyl-CoA thiolase (MCKAT) deficiency is a fatty acid oxidation disorder (inherited metabolic disorder). Individuals with this disorder are unable to convert certain fats to energy. The gene that causes MCKAT deficiency is not known.