title: Blood phenylalanine levels in mentally retarded African children: a study of 138 patients from Ibadan, Nigeria.
abstract: Blood phenylalanine levels were determined by the Guthrie microbiological inhibition technique in 138 mentally retarded, and in 88 randomly selected normal (control) Nigerian children. All the control subjects and 137 of the 138 mentally retarded children had negative Guthrie tests (6 mg/100 ml or less). In a majority of the children, the blood phenylalanine levels were 2 mg/100 ml or less. One mentally retarded child had moderately elevated blood phenylalanine level which was however much lower than the levels associated with classical phenylketonuria. The findings in the present study is in agreement with previously reported rarity of phenylketonuria in American negroes. An extensive survey of tropical Africa for phenylketonuria is, however, still desirable because regional and ethnic differences in the incidence of the disease may exist.
mesh_terms: D044383:Black People; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008607:Intellectual Disability / Q000097:blood* / Q000150:complications; D008297:Male; D009549:Nigeria; D010649:Phenylalanine / Q000097:blood*; D010661:Phenylketonurias / Q000150:complications
chemical_list: D010649:Phenylalanine