Expanded clinical spectrum of spondylocarpotarsal synostosis syndrome and possible manifestation in a heterozygous father

Abstract

We report on a 5-year-old boy with spondylocarpotarsal synostosis (SCT) syndrome who presents with disproportionate short stature, thoracic scoliosis, pes planus, dental enamel hypoplasia, unilateral conductive hearing loss and mild facial dysmorphisms. Radiographs showed abnormal segmentation of the spine with block vertebrae and carpal synostosis. In addition to the typical phenotype of SCT syndrome, he showed pronounced delay of carpal bone age and bilateral epiphyseal dysplasia of the proximal femora. The patient's father has mild short stature and unilateral hip dysplasia. Molecular studies of the filamin B gene (FLNB) revealed a homozygous mutation in the index patient while both parents were heterozygous for the mutation. In this report we expand the phenotype of SCT syndrome in a patient with a causal FLNB mutation.