[Partial monosomy 20q : a new syndrome. Regional assignment of the ADA locus on 20q132 (author's transl)].

A karyotype 46,XY,20q-(q13 leads to qter) was found in an infant with severe mental deficiency, epilepsy, and the following dysmorphic features : upward slanting palpebral fissures, hypoplastic nasal bridge, bulbous nose, long philtrum, microretrognathia, and aplasia of the middle phalanx of fingers and toes. Adenosine deaminase activity was within the hemizygous range, permitting regional assignment of the ADA locus to 20q13 leads to qter.