RESUMO
Hereditary diseases and congenital marformations have been reported to affect 2-5% of all live births; they account for up to 30% of pediatric hospital admissions, and cause about half of childhood deaths in developed countries. Available evidence suggests that genetic are important also in countries of the Eastern Mediterranean Region. The following factors may contribute to the prevalence of genetically determined disorders: the high consanguinity rates; the trend of continuing to bear children up to menopause; the general lack of public awareness about genetic diseases and the dearth of genetic services in the region. Neonatal screening tests early detect disorders in newborns for which interventions shortly after birth have obvious benefits. We aimed at screening of congenital hypothyroidism [CH], phenylketonuria [PKU], and galactosemia which are common causes of preventable mental retardation and starting their early intervention. Our study included 15.000 dried blood specimens [DBSs] from the newborns of all the ten conters of the Menoufiya governorate, as a representative random sample of the year 2007. all speciemens were analysed in neonatal screening laboratory in our genetics and endocrinology unit, pediatric department; Menoufiya University in collaboration with the central laboratories of ministry of health and population; using ELISA for TSH analysis and flourometric assay [WALLAC system, Perkin Elmer] for PKU and galactosemia screening. Preservation and transfer of DBSs were according to the recommendations of the International Society for Neonatal Screening. Because of the high costs, we randomly selected two thousands DBSs for PKU screening and another two thousands for screening of galactosemia. Out of the /5,000 DBSs, 99.84% were negative for CH [TSH < 20 ulU/ml]. Twenty five cases were borderline for CH, while 9 cases only were confirmed as CH after clinical examination and revaluation using serum samples [serum TSH > 20 ulU/ml and T4 < 0.8 ng/dl], the confirmed cases were treated according to the management schedule. So the incidence of CH in our study was 0.06%. As regards PKU screening; 93.95% of studied samples were negative [phenyl alanine < 2.1 mg/dl]. Only 21 cases were initially borderline for PKU [phenyl alanine = 2.1-3.0 mg/dl, while clinically normal] but no PKU cases were detected after revaluation. On the other side; the 2000 DBSs screened for galactosemia were negative [Galactose uridyl -1 transferase enzyme [GALT] > 3.5 u/gHb]. On conclusion, because of the high costs of mass screening for PKU and galactosemia, only screening of high risk families and neonates is recommended. On the other hand screening programs should include our more common problems as congenital deafness and hemoglobinopathies