A survey for the incidence of phenylketonuria in Guangdong, China.

A multicenter cooperative investigated the incidence of Phenylketonuria (PKU) in the central, southern and western areas of Guangdong province and its surrounding districts. Tests to measure phenylalanine (Phe) on dried blood spots on filter paper cards used BIA and thefluorescence assay. Four hundred sixty-one thousand eight hundred five (461,805) newborns were screened and 14 cases of persistent hyperphenylalaninemia (PHPA) were detected. The incidence of PHPA was 1/33,000, including 1/77,000 for classical PKU; 1 in 66,000 for hyperphenylalaninemia (HPA) and 1 in 461,805 for BH4 deficiency. A high variation in PKU incidence in the different districts was observed. The differences may be attributed to the variations in gene frequency of PKU in the different districts and to bioethical consideration especially as regards reproduction in different areas.