PHENYLKETONURIA IN COSTA-RICA - PRELIMINARY SPECTRUM OF PAH MUTATIONSAND THEIR ASSOCIATIONS WITH HIGHLY POLYMORPHIC HAPLOTYPES

A preliminary evaluation of the molecular basis of phenylketonuria (PK U) in Costa Rica was made by performing mutational analyses in the six PKU families identified to date. These studies revealed the presence of the previously reported European mutations IVS1nt5, L48S, E221G and IVS12nt1 as well as the novel mutation IVS7nt3. The combined use of t he STR, VNTR and XmnI polymorphic systems for the PAH gene resulted in a discriminant distribution of haplotypes among normal and mutant chr omosomes and suggests its potential usefulness for future diagnostic a pplications in Costa Rican PKU kindreds. This is the first report of a genetic analysis in a Central American PKU population.