Phenotype Analysis in Two Families With Otopalatodigital Syndrome Spectrum Disorder Based on FLNA Gene Variants.

Abstract

Otopalatodigital spectrum disorders (OPDSD), comprising otopalatodigital syndromes types 1 and 2 (OPD1, OPD2) and frontometaphyseal dysplasia (FMD), are rare X-linked disorders caused by FLNA gene variants, with phenotypes ranging from mild skeletal anomalies to severe multisystem malformations. We describe two unrelated cases: a 14-year-old male (P1, FMD) and an aborted fetus (P2, OPD2). Whole-exome sequencing identified hemizygous maternally inherited FLNA gene variants in P1 (c.733G>A; p.Glu245Lys) and P2 (c.3707G>A; p.Gly1236Asp, novel), expanding the OPD2 mutational spectrum (NM_001110556). P1 presented with facial dysmorphism, dental anomalies, flattened thumbs, and dermatoglyphic changes; P2 showed facial dysmorphism, skeletal and cardiac malformations, and omphalocele. These cases underscore the breadth of OPDSD phenotypic variability and add novel genetic data. Dental management demands multidisciplinary care from infancy through adolescence, including cleft repair, orthodontics for micrognathia and facial aesthetics, and treatment of dental anomalies. Early recognition, molecular diagnosis, and coordinated management are critical for improving outcomes in these complex disorders.