A variant of the alpha-thalassemia/mental retardation syndrome (ATR) due to deletion of a segment of the short arm of chromosome 16. A form in which there is no deletion is termed "alpha-thalassemia/mental retardation syndrome, nondeletion type" (q.v.). The phenotype is variable and consists of mental retardation in association with different combinations of oro-facial, genital, and other abnormalities.
