[Genetic testing and prenatal diagnosis in seven pedigrees affected with ornithine transcarbamylase deficiency]

To detect genetic variants among 7 pedigrees affected with ornithine transcarbamylase deficiency (OTCD) and provide prenatal diagnosis for them.

The pedigrees were subjected to targeted next-generation sequencing (NGS) with a gene panel for inherited metabolic diseases. Suspected pathological variants were confirmed by Sanger sequencing of the probands and their family members. Prenatal diagnosis was provided for 4 of the pedigrees.

Seven variants of the OTC gene, including c.583G>A (p.Gly195Arg), c.626C>T (p.Ala209Val), c.674C>T(p.Pro225Leu), c.482A>G (p.Asn161Ser), IVS1-2A>G, c.116G>T(p.Gly39Val), c.898delT(p.300Phefs*22), were detected, among which IVS1-2A>G, c.116G>A (p.Gly39Val) and c.898delT (p.300Phefs*22) were unreported previously. Three male fetuses were found to carry hemizygotic variants upon prenatal diagnosis. One female fetus were found to be heterozygous for a variant, and appeared to be normal at birth as well as by newborn screening.

OTC gene variant is the etiology of OTCD in the 7 pedigrees. Genetic testing of OTC could assist physicians in OTCD diagnosis and provide genetic counseling and prenatal diagnosis for the pedigrees.