A novel frameshift homozygous mutation in FAT1 gene causes ptosis, nephropathy, and syndactyly in an Emirati family: case report and literature review

Background: Single gene mutations are important causes of glomerular disease in children. Of these genes, mutations in the FAT1 gene have been recently described in the literature as a cause of nephropathy in isolated form or multisystem involvement. The spectrum of renal disease associated with FAT1 gene mutations varies from asymptomatic proteinuria and hematuria to severe nephrotic syndrome and end-stage renal disease. Case Presentation: In this case report, we describe a 3-year-old child and two other family members with a novel frameshift homozygous mutation in the FAT1 gene consistent with the diagnosis of autosomal recessive colobomatous-microphthalmia, ptosis, nephropathy, and syndactyly syndrome with variable expression of the phenotype. Conclusion: This report adds to the genotype-phenotype correlation, highlighting the clinical importance of considering FAT1 gene defects as part of the differential diagnosis for congenital ptosis, syndactyly and nephropathy, especially with multiple affected family members.