STUDIES ON A BOY WITH XXYY CHROMOSOME CONSTITUTION.

Abstract

The twelfth instance in a human of an XXYY chromosome complement is described in a 16-year-old boy. One hundred thirty-five metaphase plates from two leucocyte cultures and ten from testis and skin had a modal number of 48 chromosomes. Karyotyping demonstrated 2X-chromosomes 2Y-chromosomes, and 44 autosomes. Sex chromatin bodies were present in 23-28% of buccal epithelial cells and in testicular cells, and there were 17 drumsticks in 500 neutrophiles. Micro-orchidism and azoospermia were present. Testicular biopsy revealed diminution of germinal cells and hyalinization of seminiferous tubules, together with clumping of the Leydig cells. A small brain case (20.8 in. occipitofrontal circumference) and mental retardation (Stanford-Binet I. Q. 62) were found. He also had slight facial prognathism, webbing of the neck, and congenital infundibular pulmonary stenosis. There were no chromosomal abnormalities found in studies performed on his parents. Both the patient and many members of his immediate family had unusual dermatoglyphic findings, including low ridge counts and a high number of arches on the fingers.