Polymorphism in the 3' untranslated region of the phenylalanine hydroxylase gene detected by enzyme mismatch cleavage: evolution of haplotypes.

A polymorphism was identified in 3' untranslated region of the phenylalanine hydroxylase gene using the newly described mutation detection method, enzyme mismatch cleavage. This polymorphism, 1546 G-->A, was linked to three mutations on several haplotype backgrounds. A group of haplotypes was identified as evolving from the one ancestral haplotype on which this base substitution occurred. The possible Celtic or Viking origin of this polymorphism is discussed.