In contrast to the large X chromosome, the Y chromosome contains only 26 genes. The non-sex feature X-linked genes are also responsible for male pattern baldness. They are responsible for red-green color blindness, considered the most common genetic disorder and found most often in males. In fact, many are linked to disorders such as hemophilia, Duchenne muscular dystrophy, fragile-X syndrome and several others. There are approximately 1,098 X-linked genes, though most of them are not for female anatomical characteristics. Genes on either sex chromosome can be called sex-linked genes. Genes found only on the Y chromosome are referred to as Y-linked genes, and expressed only in males. This means that almost any gene on the X, even if it is recessive in the female, will be expressed in males. Because the additional genes in the X chromosome have no counterpart in the Y chromosome, the X genes are dominant. The X chromosome is significantly longer than the Y chromosome and contains hundreds more genes. While the chromosomes for other parts of the body are the same size and shape - forming an identical pairing - the X and Y chromosomes have different structures. It is important to remember that sex and gender have two separate definitions and many cultures include more labels than simply "male" and "female" to identify others.
Clearly, there are not only females who are XX and males who are XY, but rather, there is a range of chromosome complements, hormone balances, and phenotypic variations that determine sex." "Similarly some females are also born 46XY due to mutations in the Y chromosome. "In addition, some males are born 46XX due to the translocation of a tiny section of the sex determining region of the Y chromosome," said WHO. Others are born with three or more sex chromosomes (47XXX, 47XYY or 47XXY, etc.) and are called sex polysomies. For example, a certain X chromosome called Xq28 and a gene on chromosome 8 seem to be found in higher prevalence in men who are gay, according to a 2014 study in the journal Psychological Medicine.Ī few births out of a thousand of babies are born with a single sex chromosome (45X or 45Y) and are referred to as sex monosomies. Recent research has found that a person can have a variety of different combinations of sex chromosomes and genes, particularly those who identify as LGBT.
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