ABSTRACT
Ulnar-mammary syndrome (UMS) is a rare, autosomal dominant disorder characterized by anomalies affecting the limbs, apocrine glands, dentition, and genital development. This syndrome is caused by haploinsufficiency in the T-Box3 gene (TBX3), with considerable variability in the clinical phenotype being observed even within families. We describe a one-year-old female with unilateral, postaxial polydactyly, and bilateral fifth fingernail duplication. Next-generation sequencing revealed a novel, likely pathogenic, variant predicted to affect the canonical splice site in intron 3 of the TBX3 gene (c.804 + 1G > A, IVS3 + 1G > A). This variant was inherited from the proband's father who was also diagnosed with UMS with the additional clinical finding of congenital, sagittal craniosynostosis. Subsequent whole genome analysis in the proband's father detected a variant in the EFNA4 gene (c.178C > T, p.His60Tyr), which has only been reported to be associated with sagittal craniosynostosis in one patient prior to this report but reported in other cranial suture synostosis. The findings in this family extend the genotypic spectrum of UMS, as well as the phenotypic spectrum of EFNA4-related craniosynostosis.
Subject(s)
Abnormalities, Multiple , Breast Diseases , Craniosynostoses , Abnormalities, Multiple/genetics , Breast Diseases/genetics , Craniosynostoses/genetics , Female , Humans , T-Box Domain Proteins/genetics , Ulna/abnormalitiesABSTRACT
This report highlights the clinical features seen in duplication of 8q22.1q23.1 inherited from balanced father. It stresses the importance of obtaining a karyotype to identify the location of a large copy number variant for accurate recurrence risk estimation.
