Opitz G/BBB syndrome is an inherited condition that affects several structures along the midline of the body. The most common features are wide-spaced eyes and defects of the larynx, trachea, and/or esophagus causing breathing problems and difficulty swallowing. Affected males usually have a urethra opening on the underside of the penis (hypospadias). Other features can include mild intellectual disability, cleft lip and/or a cleft palate, heart defects, an obstruction of the anal opening (imperforate anus), agenesis of the corpus callosum, and facial abnormalities.
There are two forms of Opitz G/BBB syndrome, which are distinguished by their genetic causes and patterns of inheritance. The X-linked form is caused by mutations in the MID1 gene. Autosomal dominant Opitz G/BBB syndrome is caused by a deletion of 22q11.2, and is often referred to as 22q11.2 deletion syndrome. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.