title: Paternal hyperphenylalaninemia.
abstract: In an article published in 1981 that reported on semen studies in four men with phenylketonuria (PKU), it was concluded that semen volumes were significantly reduced. However, the index case should not have been included in the statistical analyses. In the other three cases, the men with PKU had smaller semen volumes than did the four control medical students. The significance of these data depends upon the subjects' reliability in accurately reporting abstinence from ejaculation during the preceding four days. Significant differences were not found in sperm count per milliliter, total sperm count, motility, viability, and abnormal forms of sperm. The 1981 article has aroused concerns about both the ability of men with PKU to father offspring and the outcome for children who are conceived. In the present article, the author reports on one case of paternal benign hyperphenylalaninemia from her clinic and eight cases of presumably classical PKU that were previously reported. The nine cases include a total offspring of 33. Of these 33, eight had PKU, two had milder to moderate hyperphenylalaninemia, and one undiagnosed retarded child died at the age of 8 years. The 22 other offspring seem to be normal or similar to their non-PKU mothers. Three of the fathers had no hyperphenylalaninemic offspring. Two PKU offspring were from a mating of two PKU parents. Hyperphenylalaninemic men can obviously father children, but abnormalities other than hyperphenylalaninemia have not been seen.
mesh_terms: D000328:Adult; D002648:Child; D002675:Child, Preschool; D005220:Fathers; D005260:Female; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D007223:Infant; D008297:Male; D010375:Pedigree; D010649:Phenylalanine / Q000097:blood*; D010661:Phenylketonurias / Q000235:genetics; D012098:Reproduction
chemical_list: D010649:Phenylalanine