For the purposes of scientific and medical clarity, those born with two X chromosomes are referred to as biological females by researchers and medical personnel. There are other sex chromosome combinations that result in an individual being labeled a biological female such as the combinations XXX and XO. However, they are much rarer than an XX combination. Being a biological female indicates that an individual will receive a certain set of health advantages and disadvantages.
Protection Against Certain Genetic Disorders
The presence of two X chromosomes in someone’s cells provides that person with a higher level of genetic diversity than those with an X and a Y chromosome. This is because biological females have two sets of all the genes on the X chromosome and biological males typically only have one. Only one full set is expressed in each cell; however, the set that is expressed in a cell is random. So, half of a biological female’s cells express all the genes from one X chromosome and the other half express all the genes of the remaining X. This means that, if one-half of a female’s cells are expressing a mutated gene from an X chromosome, the other cells may express another non-mutated version of that gene. As a result, females essentially have an extra layer of protection against certain genetic diseases.
Genetic diseases that are referred to as X-linked recessive are far less common in females. The group of known X-linked recessive conditions includes about 290 diseases. Some of the more well-known conditions in the group are red-green color blindness, Duchenne muscular dystrophy, and hemophilia A and B.
Stronger Immune Systems
It has been found that some of the genes in a female’s unexpressed X chromosomes may actually be expressed anyway. Because of this, the average biological female’s cells may express the X chromosome genes more often than the average male’s cells. Since the X chromosome has a good number of genes related to the immune system, this means that females have stronger immune responses.
During the COVID-19 pandemic, males were admitted to the ICU 2.84 times more often. Their mortality rate was also 1.39 times higher. This may have been the result of them generally having weaker immune responses.
Higher Rates of Autoimmune Diseases
In most cases, having a more responsive immune system is a good thing. However, it also means that there is a higher likelihood of that immune system responding to something that it should not respond to. It could, for example, mount an immune response against the body. In fact, females make up about 80 percent of the people affected by autoimmune diseases.
