NEWBORN SCREENING FOR PHENYLKETONURIA AND CONGENITAL HYPOTHYROIDISM: RESULTS FROM CLUJ CENTER, 2011-2015

Abstract

Objectives. The aim of our study was to assess the current state of newborn screening (NBS) for two innate errors of metabolism, phenylketonuria (PKU) and congenital hypothyrodism (CH) in the north-west part of Romania, in Cluj regional center (CJRC), one of the five screening centres in the country, responsible for screening from 7 counties. Material and methods. The transversal descriptive study is based on data obtained from the screening of 101,739 newborns born between 2011-2015. The screening was performed for PKU and CH based on dry blood spot (DBS) collected on standardized filter paper. The concentration of phenylalanine (Phe) and thyroid stimulating hormone (TSH) in the blood was measured through a fluorometric assay. Newborns with abnormal screening results (TSH > 18 μUI/ml and Phe > 3 mg/dl) were confirmed with CH by the dosage of free thyroxine (fT4) and with PKU or hyper-phenylalaninemia (HPA) by plasma phenylalanine determination (thin-layer chromatography method coupled with densitometry video) respectively. Results. We detected 10 cases with PKU (~ 1/10.000), 6 cases with (HPA), and 10 cases with CH, all being treated and none of them developed neurologic disorders. From a total of 115,779 newborns, 101,739 were screened (87.87%) while 14,040 were not tested (12.13%). The most frequent mutation in confirmed cases was R408W. Discussions. Counties where screening program was deficient are: Maramures 4,811 (20.26%), Bihor 3,349 (11.33%) and Sibiu, with 6,537 (30.65%) not tested newborns. In Sibiu there are maternities where the screening program is not applied. Conclusions. The high number of unscreened newborns opens the possibility of un-reversible neurologic disorders. Better organization of sampling and transportation, a correct feed-back from confirmed cases and governmental financing of the genetic analysis would increase the efficiency of the program. The number of confirmed cases claims for the future development of the program with the introduction, eventually, of other rare congenital diseases.

Keywords

• newborn screening
• phenylketonuria (pku)
• congenital hypothyroidism
• hyperphenilalaninemia