Question

What are the main diseases caused by errors in the number of sex chromosomes in the cells of an individual?

Answer 1

Humans have two sex chromosomes – the X chromosome and the Y chromosome. Females carry two copies of the X chromosome (XX) and males carry one of each (XY). The syndromes associated with an abnormal number of sex chromosomes are as follows:

• The XO syndrome also is known as the Turner syndrome due to one X missing chromosome
• XXY condition resulting in Klinefelter syndrome
• XXX condition resulting in triple-X
• XYY condition resulting in Jacobs syndrome
• XXYY condition resulting in XXYY syndrome

For example, people with Turner syndrome have only one (X) chromosome from birth. Turner females are short with broad chest and folds on the neck. The ovaries uterine tubes and Uterus are very small. They do not menstruate or undergo puberty. One in 650 males is born with two (X) chromosomes and one (Y) chromosome. It is referred to as “(47, XXY),” and the symptoms are so subtle. This includes speech and language delay. Those who develop more symptoms as adults are referred to as having Klinefelter syndrome.