Chromosome abnormalities can occur in both autosomes and sex chromosomes. When occurring in sex chromosomes there could be different outcomes. One of them is trisomy, where men have two X chromosomes and one Y chromosome. Because of this they have 47 chromosomes and their karyotype is 47XXY. It is called Klinefelter syndrome. This anomaly is seen only with men. Signs of it usually are noticed during puberty, where there are some changes in the outlook than a normal male development.
Signs of Klinefelter syndrome
Men with this anomaly in most cases are sterile, low development of the testicles ( testicular atrophy), gynecomastia ( increased size of the chest) and hyalinization of the seminiferous tubules. There is also a presence of sex chromatin (Barr) body. This body is typical of one of the two chromosomes in women. Having two X chromosomes in men is the reason for the forming of this body. There is also less amount pubic hair than normal. The same is for the hair of the armpits and face. Body proportions are different than normal as well. Usually there are long legs and short trunk, as well as same sized shoulders and hips.
Tests and treatment
Determining this anomaly can happen by performing tests such as karyotyping and semen count. Hormone levels could be checked as well by blood tests. Usually the analyzed hormones are Estradiol, Follicle stimulating hormone, Lutinizing hormone and Testosterone.
As treatment testosterone could be prescribed to the patient. The purpose of this is to grow more hair, improve muscles and concentration, increase strength, mood and self esteem.
How often does it occur?
The frequency of this anomaly is one in 500 newborn males. There are cases where there could be more than two X chromosomes. For example there could be three (48XXXY). That means there are 44 autosomes and 4 sex chromosomes in the child’s cells. The larger number of X chromosomes makes it more likely to have mental impairment.