EP06.20: Role of next‐generation‐sequencing in the etiological diagnosis of prenatal bilateral renal agenesis

To assess the diagnostic yield of Next Generation Sequencing (NGS) of both, CAKUT targeted gene panel and clinical exome sequencing (CES) applied to the etiological diagnosis of fetal bilateral renal agenesis (BRA). Seven cases of fetuses with prenatal sonographic diagnose of bilateral renal agenesis (isolated or associated with other structural anomalies), and normal microarray analysis, detected in our Fetal Nephrourological Unit in the last 2 years. All women opted for TOP. In all cases the whole fetal exome was sequenced and CAKUT targeted genes or CES, in cases of complex BRA, were interpreted post-mortem after the pathological findings described at autopsy. Among the 4 CAKUT panels performed in isolated BRA, 2 pathogenic variants: FRAS1, ITG8 and 1 VUS (GREBL1) were found. On the other hand, 3 clinical exome sequencing were performed in complex BRA obtaining 1 pathogenic variant (FRAS1) CAKUT gene panels could find the causative genetic variant in more than half of isolated fetal BRA and provide valuable information for prenatal counselling regarding subsequent pregnancies. However, as new genes causative of BRA are still being identified, whole exome sequencing will have a promising role in the etiological diagnosis of this condition.