Clinical phenotype and genetic analysis of a fetus with Glutaracidemia type II C / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical phenotype and genetic variants of a fetus with Glutaracidemia type II C (GA II C).@*METHODS@#Clinical data of a 32-year-old pregnant woman and her fetus with GA II C diagnosed at the Third Affiliated Hospital of Zhengzhou University in December 2021 due to the enlargement and enhanced echo of the kidneys and oligohydramnios fluid at 17 weeks were analyzed retrospectively. Amniotic fluid sample of the fetus and peripheral blood samples of the couple were collected for whole exome sequencing (WES). Candidate variants were verified by Sanger sequencing. Copy number variation (CNV) was detected by using low-coverage whole genome sequencing (CNV-seq).@*RESULTS@#At 18 weeks' gestation, ultrasound revealed that the fetus had enlargement and enhanced echo of the kidneys along with no echo of renal parenchymal tubular fissure and oligohydramnios. MRI at 22 weeks' gestation confirmed that both kidneys were enlarged with uniformly increased abnormal T2 signal and decreased DWI signal. The volume of both lungs was small, with slightly higher T2 signal. No CNV was detected in the fetus. WES revealed that the fetus has harbored compound heterozygous variants of the ETFDH gene, namely c.1285+1G＞A and c.343_344delTC, which were inherited from its father and mother, respectively. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were classified as pathogenic (PVS1+PM2_Supporting+PS3_Supporting; PVS1+PM2_Supporting+PM3).@*CONCLUSION@#The c.1285+1G＞A and c.343_344delTC compound heterozygous variants of the ETFDH gene probably underlay the disease in this fetus. Type II C glutaric acidemia may manifest as bilateral kidney enlargement with enhanced echo and oligohydramnios. Discovery of the c.343_344delTC has enriched the spectrum of ETFDH gene variants.

Enlarged multicystic dysplastic kidneys with oligohydramnios during infancy caused by NPHP3 gene mutation / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical features and genomic abnorm ality of a fetus enlarged multicystic dysplastic kidneys with oligohydramnios caused by NPHP3 gene mutation.@*METHODS@#The fetuse was found to have multicystic dysplastic kidneys with oligohydramnios upon ultrasonography during the second trimester. Following induced abortion, fetal tissue was collected for the extraction of DNA, chromosomal microarray analysis (CMA) and whole exome sequencing (WES). Sanger sequencing was used to verify the suspected variants in the family.@*RESULTS@#Antenatal ultrasound examination at 19 weeks showed "polycystic" kidneys with Oligohydramnios. Delivery was by induced labour because of the critically low amniotic fluid volume. Testing of CMA was normal. WES showed a compound heterozygous mutation of c.1817G>A, p.W606X; c.432dupA, p.E145Rfs*18 mutations are novel mutations in this study.@*CONCLUSION@#The research may further expand the NPHP3 gene mutation spectrum. Enlarged multicystic dysplastic kidneys with oligohydramnios caused by NPHP3 gene mutation at least include one or two splice site mutation, frameshift mutation or nonsense mutation foetal poor prognosis.