Identification of truncated variants in GLI family zinc finger 3 (GLI3) associated with polydactyly.

Abstract

Polydactyly is a prevalent congenital anomaly with an incidence of 2.14 per 1000 live births in China. GLI family zinc finger 3 (GLI3) is a classical causative gene of polydactyly, and serves as a pivotal transcription factor in the hedgehog signaling pathway, regulating the development of the anterior-posterior axis in limbs. Three pedigrees of polydactyly patients were enrolled from Hunan Province, China. Pathogenic variants were identified by whole-exome sequencing (WES) and Sanger sequencing. Three variants in GLI3 were identified in three unrelated families, including a novel deletion variant (c.1372del, p.Thr458GlnfsTer44), a novel insertion-deletion (indel) variant (c.1967_1968delinsAA, p.Ser656Ter), and a nonsense variant (c.2374 C > T, p.Arg792Ter). These variants were present exclusively in patients but not in healthy individuals. We identified three pathogenic GLI3 variants in polydactyly patients, broadening the genetic spectrum of GLI3 and contributing significantly to genetic counseling and diagnosis for polydactyly.