[Diagnosis of glutaric acidemia type ⅡC by fetal whole exome sequencing]

To explore the genetic basis of a fetus with enlargement and enhanced echo of the kidneys.

The imaging data of the fetus were collected, in addition with 20 mL amniotic fluid sample and 2 mL peripheral blood samples of both parents. Amniotic DNA was extracted for library construction and whole exome sequencing, and Sanger sequencing was carried out to verify candidate variant associated with the fetal phenotype.

Prenatal ultrasound showed that the fetus had enlargement and enhanced echo of the kidneys, in addition with many small renal cysts. Whole exome sequencing showed that the fetus carried pathogenic compound heterozygous variants of the ETFDH gene, namely c.3G>C and c.1436dupA. Sanger sequencing of the family suggested that the variants were inherited from its mother and father, respectively.

By combining its clinical manifestations and results of whole exome sequencing, the fetus was diagnosed as glutaric acidemia type ⅡC due to the compound heterozygous variants of the ETFDH gene. Above results have provided a basis for prenatal diagnosis and genetic counseling. Fetal exome sequencing has provided an important tool for prenatal diagnosis.