APA Dictionary of Psychology

a genetic disorder marked by abnormalities along the midline of the body, including facial anomalies, such as widely spaced eyes and a high nose bridge; defects of the larynx, trachea, and esophagus that make breathing or swallowing difficult; and a urethral opening on the ventral side of the penis. Mild intellectual developmental disorder occurs in fewer than 50% of cases, most likely caused by structural defects in the brain. About half of affected individuals also have cleft lip with or without a cleft palate. The condition is genetically heterogeneous, with an X-linked form and an autosomal form considered to be among the 22q11.2 deletion syndrome spectrum disorders. Also called Opitz BBB (or BBB/G) syndrome (from the names of the affected families originally reported); Opitz–Frias syndrome. [reported in 1969 by U.S. geneticist John M. Opitz (1935–  ) and Chilean-born U.S. geneticist Jaime L. Frias]