title: Compound heterozygotes in hyperphenylalaninaemia.
abstract: Three children with hyperphenylalaninaemia and hyperphenylalaninaemic mothers are presented. At least one of the affected children was a compound heterozygote for hyperphenylalaninaemia and phenylketonuria. The families were examined by an L-phenylalanine loading test, by direct determination of phenylalanine hydroxylase and/or a loading test with hepta-deuterophenylalanine. We conclude that most of the patients with moderately elevated serum phenylalanine should have the genotype hyperphenylalaninaemia/phenylketonuria, i.e. they are compound heterozygotes.
mesh_terms: D005260:Female; D006579:Heterozygote; D006801:Humans; D007223:Infant; D008297:Male; D010641:Phenotype; D010649:Phenylalanine / Q000097:blood / Q000235:genetics*; D010661:Phenylketonurias / Q000235:genetics*
chemical_list: D010649:Phenylalanine