Phenylketonuria is a common amino acid metabolic disease. Due to the enzyme defect in the metabolic pathway of phenylalanine (PA), phenylalanine can't be converted into tyrosine, which leads to the accumulation of phenylalanine and its keto acids, and a large number of them are excreted from urine.
The disease is common in hereditary amino acid metabolic defects, and its inheritance mode is autosomal recessive inheritance.
The clinical manifestations are uneven. The main clinical manifestations are mental retardation, psychotic symptoms, eczema, skin scratch sign, depigmentation, rat odor and abnormal EEG.
If early diagnosis and early treatment can be achieved, the aforementioned clinical manifestations may not appear, intelligence may be normal, and EEG abnormalities may recover.
Extended data: Symptoms of phenylketonuria are:
1, growth and development:
The main performance is slow growth and development. Physical growth retardation is mainly manifested as short stature, malnutrition, and mental retardation, which is also the most obvious feature of phenylketonuria infants. After 4 ~ 9 months of birth, the IQ of normal children of the same age will be significantly lower. Due to the development of language,
2. Mental symptoms:
Due to the slow development of the brain, many children's brain tissue has cerebellar malformation due to atrophy, which makes children have repeated convulsions, increased muscle tension, knee tendon reflex and achilles tendon reflex, and their mental state is often excited, irritable, hyperactive or sleepy.
3, fur performance:
Because children's skin is very easy to dry, children often scratch and scratch, and eczema is prone to occur after a long time; In addition, due to the lack of enzymes in children, patients accumulate a lot of phenylalanine, which can inhibit tyrosinase and reduce the synthesis of melanin, so children's hair is light and brown.
Reference: Baidu Encyclopedia of Phenylketonuria