ANALYSIS OF FREQUENCY OF PHENYLKETONURIA AMONG INSTITUTIONALIZED
Abstract
Introduction: Phenylketonuria (PKU) is a genetic disease, which is caused by deficiency in phenylalanine hydroxylase (PAH) enzyme. Untreated patients will develop a severe mental retardation, which is irreversible. In this study, the incidence of the PKU disease among isolated mentally retarded residents in institutions in Isfahan, was investigated.
Methods: A total number of 1541 patients were involved in the study. Of the patients studied, 611 with no known reason for their mental retardation were chosen for blood sampling. Blood samples were collected on filter papers and examined by Gutheri bacterial inhibition assay (GBIA), which is specific for PKU In patients with positive test, the serum phenylalanine was quatitavely analyzed using high pressure liquid chromatography, HPLC.
Results: Among the patients examined, 33 were found positive. Quantitative analysis of phenylalanine allowed classification of the patients, indicating 600 with classical, 36% with moderate, and 3% with mild type of PKU Furthermore; it was found that in 68% of the cases, parents are third grade relative.
Discussion: The results obtained in this screening study indicated that 2.1% of the patients in the institutions for mentally related in Isfahan suffered from PKU The incidence of the disease is relatively high compare to the reports from other countries. Since, a large number of patients (68%) are the results of consanguineous marriages, this kind of marriage could be considered as one of the important factors involved in the prevalence of PKU in Isfahan.
Methods: A total number of 1541 patients were involved in the study. Of the patients studied, 611 with no known reason for their mental retardation were chosen for blood sampling. Blood samples were collected on filter papers and examined by Gutheri bacterial inhibition assay (GBIA), which is specific for PKU In patients with positive test, the serum phenylalanine was quatitavely analyzed using high pressure liquid chromatography, HPLC.
Results: Among the patients examined, 33 were found positive. Quantitative analysis of phenylalanine allowed classification of the patients, indicating 600 with classical, 36% with moderate, and 3% with mild type of PKU Furthermore; it was found that in 68% of the cases, parents are third grade relative.
Discussion: The results obtained in this screening study indicated that 2.1% of the patients in the institutions for mentally related in Isfahan suffered from PKU The incidence of the disease is relatively high compare to the reports from other countries. Since, a large number of patients (68%) are the results of consanguineous marriages, this kind of marriage could be considered as one of the important factors involved in the prevalence of PKU in Isfahan.
Keywords
Phenyl ketonuria, Phenylalanine Hydroxylase, Gutheri test, Screening