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Opitz G/BBB syndrome

Other Names for this Disease
  • BBB syndrome
  • G syndrome
  • GBBB syndrome
  • Hypertelorism hypospadias syndrome
  • Hypertelorism with esophageal abnormality and hypospadias
More Names
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What are the signs and symptoms of Opitz G/BBB syndrome?

Opitz G/BBB syndrome mainly affects structures along the midline of the body. The most common features of the condition are wide-spaced eyes (hypertelorism); defects of the larynx, trachea, and/or esophagus causing breathing problems and difficulty swallowing (dysphagia); and in males, the urethra opening on the underside of the penis (hypospadias). Mild intellectual disability occurs in fewer than 50 percent of people with Opitz G/BBB syndrome, and is most likely caused by structural defects in the brain. About half of affected individuals also have cleft lip with or without a cleft palate. Some have cleft palate alone. Heart defects, an obstruction of the anal opening (imperforate anus), and brain defects such as an absence of the tissue connecting the left and right halves of the brain (agenesis of the corpus callosum) occur in less than 50 percent of those affected. Facial abnormalities that may be seen in this disorder can include a flat nasal bridge, thin upper lip, and low set ears. These features vary among affected individuals, even within the same family. The signs and symptoms of the autosomal dominant form of the condition are comparable to those seen in the X-linked dominant form. However, the X-linked form of Opitz G/BBB syndrome tends to include cleft lip with or without cleft palate, while cleft palate alone is more common in the autosomal dominant form. Females with X-linked Opitz G/BBB syndrome are usually mildly affected, as hypertelorism may be the only sign of the disorder.[1]
Last updated: 6/17/2011

  1. Opitz G/BBB syndrome. Genetics Home Reference. November 2007; Accessed 6/17/2011.