Rare Diseases in Uruguay: Focus on Infants with Abnormal Newborn Screening

Introduction: Newborn Screening Program (NBS) in Uruguay includes congenital hypothyroidism (CHT), phenylketonuria (PKU), congenital adrenal hyperplasia (CAH), cystic fibrosis (CF), medium chain acyl-CoA dehydrogenase deficiency (MCADD), and Congenital Hearing Loss (CHL). Objetives: This study describe the epidemiological characteristics of newborns with abnormal neonatal screening tests diagnosed by blood drop and otoacoustic emissions in Uruguay. Results: Cases with abnormal NBS tests (399 newborns; 0.17%) were compared to the newborns with normal tests in the same period (239,240). Prevalence rates (per 10,000 livebirths) were 10.00 for CHL; 3.70 for CH; 1.20 for CF; 0.59 for CAH; 0.54 for PKU; 0.13 for MCADD. The Department of Artigas had the highest rate of abnormal tests. Lower maternal education, less prenatal care, increased prematurity rate and neonatal depression were more frequent in in mothers whose children had CHL. Conclusions: This is the first study evaluating the characteristics of newborns with abnormal screening in Uruguay. Because these results may impact the planning of health services, data transmission between clinical care and public health systems is needed to improve both follow-up and management.