Clinical Application of Genetic Testing for Fetal Agenesis of the Corpus Callosum in Prenatal Diagnosis.

BACKGROUND

This study aimed to investigate the clinical application of genetic testing in the prenatal diagnosis of fetal agenesis of the corpus callosum (ACC).

METHODS

Fetuses with ACC confirmed by prenatal systematic ultrasound and fetal MRI imaging underwent invasive prenatal diagnostic procedures. Amniotic fluid samples from the fetuses were collected for karyotype analysis and/or chromosomal microarray analysis (CMA). For ACC fetuses with normal karyotype and/or CMA results, whole-exome sequencing (WES) was further performed.

RESULTS

Among the 15 ACC fetuses, karyotype analysis was performed in 14 cases, with one case (7.14%, 1/14) showing an abnormal chromosomal karyotype. CMA was performed in 14 cases, with pathogenic or likely pathogenic copy number variations (CNVs) detected in 4 cases (28.57%, 4/14), including microdeletions at 13q32.2q34, 18q21.2q21.31, 16p13.3, and 16p12.2. Among the 8 ACC fetuses with normal karyotype analysis and/or CMA re-sults, WES was further performed on both the fetuses and their parents, revealing two likely pathogenic variants in two cases (25%, 2/8) involving the FOXG1 and B3GALNT2 genes.

CONCLUSIONS

Prenatal genetic diagnosis is of significant importance for ACC fetuses. CMA demonstrates a higher detection rate than karyotyping. WES can provide additional genetic diagnostic insights for ACC fetuses with normal karyotype and/or CMA.