385 - The Landscape of Genetic Testing and Associated Anomalies for Prenatally Identified Cystic Renal Malformations
Friday, April 25, 2025
5:30pm – 7:45pm HST
Publication Number: 385.6774
Courtney Verscaj, Boston Children's Hospital, Boston, MA, United States; Tabitha Poorvu, Boston Children's Hospital, Boston, MA, United States; Monica Wojcik, Boston Children's Hospital, Boston, MA, United States
Neonatal-Perinatal Medicine Fellow Boston Children's Hospital Boston, Massachusetts, United States
Background: Renal cystic changes can range from mild small unilateral cysts to bilateral multi-cystic dysplastic kidneys. The overall prevalence of cystic malformations can range from 0.44 cases per 10,000 births for those with a genetic etiology to 4.1 cases per 10,000 births for apparently sporadic malformations (Raina et. al., AJKD, 2021). Therefore, cystic renal diseases are relatively common and result in a wide spectrum of medical outcomes; however, the yield of genetic testing and the non-renal phenotypic spectrum remains poorly understood. Objective: To identify genetic syndromes resulting in cystic renal diseases and to define the spectrum of anomalies present in these conditions. Design/Methods: Retrospective observational study of pregnancies from 2021 to October 2024 referred to the Fetal Care and Surgery Center at Boston Children’s Hospital. The data were abstracted from the electronic medical record, including MRI and ultrasound findings, genetic testing, and molecular diagnoses. Results: Of 6,365 total referrals, 110 pregnancies (1.7%) were affected by a suspected cystic renal malformation. The renal phenotypes ranged from renal cysts without apparent dysplasia (n=16), to unilateral multicystic dysplastic kidney (MCDK) or cystic dysplasia (n=79) and bilateral MCDK/cystic dysplasia (n=8). Additional anomalies were identified prenatally in 30% of pregnancies (Table 1).
Prenatal genetic testing was performed in 19 patients (17%) and was diagnostic in 2 patients (10%). The overall yield of genetic testing including postnatal testing was 6 of 32 pregnancies, 19%. The diagnoses included Autosomal Dominant Polycystic Kidney Disease (ADPKD), Autosomal Recessive Polycystic Kidney Disease (ARPKD), HNF1B associated renal cysts, 22q11.2 deletion syndrome, Bakarat syndrome, Beckwith-Wiedemann and Wolf-Hirschhorn syndromes. For 2/6 diagnoses (HNF1B associated renal cysts and Bakarat syndrome), the renal cysts were the only presenting prenatal phenotype.
Conclusion(s): Renal cystic changes may be the only presenting sign of a genetic syndrome, and are frequently accompanied by other malformations. Therefore, there is utility in considering a broad molecular genetic diagnostic evaluation for patients with cystic malformations, including those without additional anomalies, for improved comprehensive prenatal counseling, multisystemic assessment, and postnatal care planning.
