I. How is the diagnosis and typing of phenylketonuria 1. The diagnosis of phenylketonuria in patients is based on the symptoms of mental retardation, yellow hair, white skin color, motor and language development backwardness in children, and can be diagnosed by increased blood phenylalanine in laboratory tests. However, at present, in some places, doctors are not sufficiently aware of this disease, and when they encounter such patients, they fail to think of this disease and do not do relevant tests, which often leads to missed diagnosis or misdiagnosis, so this disease needs the attention of the majority of doctors. The screening of neonatal diseases currently carried out can enable PKU to be diagnosed before the onset of the disease, and early treatment has been carried out, so the onset of PKU children are less common than before.
2. Typing of phenylketonuria Diagnosis of phenylketonuria is only a partial diagnosis, and there are different types of phenylketonuria due to the pathogenesis of the disease, and different treatment methods for different types, so once PKU is diagnosed, early typing is needed. Firstly, by urinary pterin analysis and erythrocyte dihydropteridine reductase activity measurement, it is divided into 2 major categories of normal and abnormal tetrahydropterin metabolism.
Second, there are 4 types of PKU with normal hydropteridine metabolism as follows: 1. Classic PKU: Phenylalanine concentration 31 200 mmol/L, ineffective for tetrahydrobiopterin treatment.
2. Mild hyperphenylalaninemia: blood phenylalanine concentration of 120 mmol/L-360 mmol/L. 3. Moderate hyperphenylalaninemia: blood phenylalanine concentration of 360 mmol/L-1,200 mmol/L. 4. Tetrahydrobiopterin-responsive phenylketonuria: phenylketonuria that is effective to tetrahydrobiopterin therapy.
There are 3 types of PKU with abnormal tetrahydropteridine metabolism: 1. 6-Pyruvoyltetrahydropteridine synthase deficient type: elevated urinary neochlorine concentration, decreased biopterin concentration, elevated blood phenylalanine, effective for tetrahydrobiopterin treatment.
2, Dihydropteridine reductase deficiency type: blood erythrocyte dihydropteridine reductase activity is decreased, blood phenylalanine is elevated or normal, elevated to tetrahydrobiopterin treatment is effective, blood erythrocyte dihydropteridine reductase activity decreased.
3, guanosine triphosphate cyclic hydrolase I deficiency type: urine neotransferrin concentration and biotransferrin concentration are decreased, blood phenylalanine is elevated or normal, elevated to the tetrahydrobiopterin treatment is effective.