Part 1 of Essay
, also called testicular dysgenesis, is the phenotype of the 47,XXY genotype and is characterized by male hypogonadism and infertility. is probably the most common chromosomal variation found in humans. In random surveys, it is found to appear about once in every 500 to one in every 1,000 live born males. Since the larges ....

Part 2 of Essay
.... number of 46. This extra sex (X) chromosome causes the distinctive make-up of these boys. All men have one X chromosome and one Y chromosome, but sometimes a variation will result in a male with an extra X. This is and is often written as 47,XXY. There are other, less common variations such as 48,XXYY; 48,XXXY; 49,XXXXY; and XY/XXY mosaic. All of these are considered variants. The major effect of the extra X chromosome in boys with seems to be the function of the testes. The testes produce the major male s ....