Maple syrup urine disease, also called BCKD deficiency, is a rare inborn error of metabolism (IEM) and autosomal recessive disorder caused by a defective BCKDHA, BKCDHB or DBT gene. These genes code for a protein which is vital in the breakdown of amino acids, specifically the amino acids leucine, isoleucine and valine. This disorder is characterized by a large accumulation of these amino acids in the body. Symptoms of the disorder include a distinct maple syrup smell of the urine, vomiting, lethargy, abnormal movements and delayed development. Treatment includes long-term dietary management which aims to restrict the consumption of branched-chain amino acids. It is estimated that maple syrup urine disorder affects 1 in 185,000 infants globally. This number increases significantly when looking specifically at Old World Order Mennonites, where the prevalence is 1 in 380 infants.
References
Maple Syrup Urine Disease References
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