Satellited chromosome 9 in a boy with multiple anomalies

A 5-year-old boy with multiple congenital anomalies showed a satellited long-arm chromosome 9, a previously undescribed abnormality. Various banding analyses of his chromosomes and those of his parents indicated that a reciprocal translocation, t(9;22)(q34.3;q11.21), occurred in the father's gonad, and one of the translocation chromosomes was then transmitted to the patient. Thus, the patient's karyotype was interpreted as 46,XY,-9,+psudic(9),t(9;22)(q34.3;q11.21). He showed several features similar to those of the Williams syndrome. The gene(s) responsible for the syndrome thus could be at either 9q34.3-qter or 22pter-q11.2. Southern blot analysis of the patient's DNA indicated the presence of two copies of the argininosuccinate synthetase gene which had been assigned to 9q34.1-qter. In view of the fact that the 9q34.3-qter segment is monosomic in the patient, the gene locus was deduced to be at 9q34.1-q34.2 segment.