Clinical and Molecular Aspects of Craniofrontonasal Syndrome due to Contiguous Gene Deletion Involving AWAT2, EFNB1, EDA, OTUD6A, and PJA1 Genes

Abstract

AbstractCraniofrontonasal syndrome (CFNS; Online Mendelian Inheritance in Man [OMIM] 340110) is an infrequent X linked disorder characterized by specific facial features and digital abnormalities with or without visceral anomalies. There is a peculiar paradoxical difference in severity of the phenotype in heterozygous females compared to hemizygous males. Here, we present a case where the mother, with clinical features of the syndrome, had terminated her previous pregnancy as the fetus had partial agenesis of the corpus callosum. Exome sequencing of the mother revealed no pathogenic variants related to the phenotype. Chromosomal microarray revealed 1.3-Mb pathogenic heterozygous deletion in chromosome X encompassing the Xq13.1 region with five OMIM genes, including EFNB1 gene related to craniofrontonasal syndrome. Detailed phenotyping of the parents and exact genetic etiology with molecular mechanism is important to arrive at a definitive diagnosis crucial for genetic counseling and definitive prenatal testing.