Abstract
Microcephaly observed at birth in 2 first cousins lead to the recognition of phenylketonuria in their mothers, 24- and 23-year-old sisters with blood phenylalanine around 1, 2 mmol/l who had never been treated and had no overt mental retardation. PCR amplification and direct sequencing of exon 7 of the phenylalanine hydroxylase gene in one sister revealed a homozygous G → A transition leading to a ARG → GLN substitution at codon 261, a mutation which has recently been associated with mild PKU (Y. Okano et al., Am J Hum Genet 46:18-25, 1990). A positive/negative PCR amplification system employing wild type and 3′end-mutation specific primers was used to confirm homozygosity for this mutation in both sisters with PKU and heterozygosity in their parents and an unaffected sister. We conclude that (1) homozygosity for the 261 ARG → GLN mutation indeed can result in a mild variant of PKU with little or no mental retardation, but that (2) elevation of blood phenylalanine in such individuals suffices to cause the maternal PKU syndrome.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Superti-Furga, A., Steinmann, B., Due, G. et al. 88 MATERNAL PKU SYNDROME IN COUSINS CAUSED BY MILD, UNRECOGNIZED PHENYLKETONURIA IN THEIR MOTHERS HOMOZYGOUS FOR THE PHENYLALANINE HYDROXYLASE 261 ARG – GLN MUTATION. Pediatr Res 28, 291 (1990). https://doi.org/10.1203/00006450-199009000-00112
Issue Date:
DOI: https://doi.org/10.1203/00006450-199009000-00112