<unk>  <unk>  is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine. Untreated,<unk>  can lead to intellectual disability, seizures, behavioral problems, and mental disorders. It may also result in a musty smell and lighter skin. A baby born to a mother who has poorly treated<unk>  may have heart problems, a small head, and low birth weight.<unk>  is a genetic disorder inherited from a person's parents. It is due to mutations in the PAH gene, which results in low levels of the enzyme phenylalanine hydroxylase. This results in the buildup of dietary phenylalanine to potentially toxic levels. It is autosomal recessive, meaning that both copies of the gene must be mutated for the condition to develop. There are two main types, classic<unk>  and variant<unk> , depending on whether any enzyme function remains. Those with one copy of a mutated gene typically do not have symptoms. Many countries have newborn screening programs for the disease. Treatment is with a diet that (1) is low in foods that contain phenylalanine, and which (2) includes special supplements. Babies should use a special formula with a small amount of breast milk. The diet should begin as soon as possible after birth and be continued for life. People who are diagnosed early and maintain a strict diet can have normal health and a normal life span. Effectiveness is monitored through periodic blood tests. The medication sapropterin dihydrochloride may be useful in some.<unk>  affects about 1 in 12,000 babies. Males and females are affected equally. The disease was discovered in 1934 by Ivar Asbjørn Følling, with the importance of diet determined in 1953. Gene therapy, while promising, requires a great deal more study as of 2014.
Phenylketonuria
Hawkinsinuria
Homocystinuria
Alkaptonuria
3-Methylglutaconic aciduria
2-Hydroxyglutaric aciduria
Alpha-aminoadipic and alpha-ketoadipic aciduria
Aspartylglucosaminuria