Supplementary Material for: CRB2-Related Syndrome in Two New Patients: Three Novel Variants

Introduction: The Crumbs homolog-2 (CRB2)-related syndrome is an extremely rare genetic disorder characterized by congenital hydrocephalus, steroid-resistant nephrotic syndrome, and cardiac anomalies. It is caused by biallelic variants in the CRB2 gene. Case Presentation: Herein, two new patients are presented including congenital hydrocephalus, nephrotic syndrome, scimitar syndrome, and severe cardiac anomalies. CRB2 related syndrome was considered with the present clinical findings and whole exome sequencing revealed three novel variants in CRB2 gene. Microcephaly, ventricular hypertrophy, anomalous pulmonary venous return, pulmonary sequestration, and thymus hypoplasia were presented only in the current patients. Variants in exon 2 (c.335G>A, p.Cys112Tyr) and intron 2 (c.419-2A>G) were reported only in the presented report. In addition, the first likely pathogenic splice site variant was reported in this report. Conclusion: Accurate diagnosis is crucial for increasing clinical awareness, and offering genetic counseling to affected families.