The Spondylocarpotarsal Synostosis Syndrome Case with Ventricular Septal Defect Caused by a Homozygous Frameshift Variation in FLNB

Abstract

Spondylocarpotarsal synostosis syndrome (SCT) (OMIM: 272460), an autosomal recessive disorder, is characterized by block vertebrae, carpal–tarsal synostosis, and disproportionate short stature. The clinical features of SCT include dysmorphic facial traits, cleft palate, hypoplastic tooth enamel, brachydactyly, clinodactyly, limited joint movement, and mixed hearing loss. SCT is associated with biallelic nonsense and frameshift pathogenic variants in the FLNB gene. An 8-year-old patient was referred with suspected skeletal dysplasia. The patient presented with short stature, scoliosis, carpal–tarsal synostosis, and ventricular septal defect (VSD). Clinical exome sequence analysis revealed a homozygous frameshift variation in the FLNB gene (c.219_222dup p.Met75Profs*17). No other pathogenic variations in genes related to VSD were found. This study aims to discuss novel clinical findings related to the genotype–phenotype association. To the best of our knowledge, this is the first reported case of SCT with VSD.