Disease spectrum and genetic profiles of neonatal inborn errors of metabolism in selected areas of Nanning city / 中国新生儿科杂志

ABSTRACT

Objective:To study disease spectrum and genetic profiles of inborn errors of metabolism (IEM) among newborns in selected areas of Nanning city.Methods:From July 2019 to December 2021, neonates born and received IEM screening in our hospital were prospectively enrolled. Heel blood samples were tested using tandem mass spectrometry as IEM screening. Neonates with positive results were called back for recheck. Whole exome sequencing was used to detect possible pathogenic genes in suspected cases and IEM was diagnosed combining clinical manifestations. Sanger sequencing method was used for the diagnosed neonates and their parents to confirm the diagnoses.Results:A total of 16 207 live-birth neonates were enrolled. For initial IEM screening, 1 423 neonates were positive (8.8%) and 1 311 were called back (92.1%). 15 cases were suspected with IEM and 8 were diagnosed. The overall detection rate was 1∶2 026. Among 8 confirmed cases, 4 cases had amino acid metabolism disorders (2 cases of phenylketonuria, 1 case of Citrin deficiency and 1 case of tyrosinemia), 2 cases had organic acid metabolism disorders (1 case of methylmalonic acidemia and 1 case of glutaric acidemia) and 2 cases had fatty acid oxidation disorders (1 case of carnitine palmitotransferaseⅡdeficiency and 1 case of primary carnitine deficiency). 5 cases had homozygous genetic variants (2 in PAH, and 1 in SLC25A13, SLC22A5 and FAH, respectively) and 3 had heterozygous genetic variants (1 in CPT2, MUT, and GCDH, respectively). During follow-up, all 8 cases had normal growth and developmental outcomes after standardized treatment.Conclusions:The overall detection rate of IEM is high, with varied genetic profiles in selected areas of Nanning. Timely genetic testing may lead to early diagnosis and treatment and improve the quality of life of neonates.