Abstract

GUTIERREZ, Reinaldo; GUTIERREZ, Enna; BARRIOS, Bárbara  and  MARCOS, Ligia. CORRELATION BETWEEN THE GENOTYPE AND THE BIOCHEMICAL PHENOTYPE IN CUBAN PATIENTS WIHT HYPERPHENYLALANINEMIAS. Rev Cubana Pediatr [online]. 2005, vol.77, n.1. ISSN 0034-7531.

Phenylketonuria is a recessive autosomal disease caused by mutations in the gene of the phenylalanine hydroxylase enzime. It has a wide phenotypic spectrum that depends mainly on the residual activity of the enzyme. Objectives: To detemine the genotype-chemical phenotype correlation in patients whose genotype is known, according to the residual activity of the mutated enzime expressed in vitro in accordance with the gene's database (http://www.mcgillca/pah/db). Methods: We evaluated the biochemical and molecular data of 23 hyperphenylalaninemic individuals. The concentration of phenylalanine at birth and the tolerance to phenylalanine at 5 years of the beginning of the treatment, as well as the residual activity in vitro of each of the mutations, were taken into account. Results and conclusions: According to the data base of the PAH gene and of the above parameters, 12 patients had severe mutations, 10 intermediate and 1 benign. Our study showed that there is a genotype-biochemical phenotype coincidence in 78.2 % of the subjects with phenylketonuria that were studied.It was proved that mutations in the PAH gene are the main factor in the determination of the metabolic phenotype in patients with hyperphenylalaninemia.

Keywords : Hyperphenylalaninemia; phenylketonuria; genotype; phenotype; phenylalanine hydroxylase.