778 9P TRISOMY CONFIRMED BY GENE DOSAGE EFFECT: REPORT OF 2 PATIENTS

Clinical features in patients with 9p duplication have been well delineated (de Grouchy 1977). This report is prompted by two patients seen in the Genetics Clinic at University of California Irvine Medical Center and University of California Los Angeles. Upon examination each patient demonstrated the following characteristics: brachycephaly, bulbous nose, worried facial expression, small deep-set eyes, short upper lip, down-turned mouth, large external ears, and varying degrees of mental retardation. The chromosomal karyotype in each patient revealed partial 9p duplication, one as a result of tandem duplication of 9p bands (p13→p24) and the second patient with an extra number 9 with deletion of the long arm distal to q13. Further study revealed both patients to have elevated galactose-1-phosphateuridyl-transferase (GALT) levels. These two patients demonstrate two significant observations: 1) the presence of minor dysmorphic features and varying mental retardation occurring with duplication of all or a segment of 9p; 2) the elevated levels of GALT certainly aided the interpretation of unusual chromosomal abnormalities.