Are born bad kids caused by super male syndrome?

Recently, a fetus in Sichuan was found to be a chimera super male, which caused heated discussion. The mother of the fetus decided to induce abortion. For a time, "super male syndrome" has once again entered people's field of vision. Today, let's talk about whether "super male syndrome" really leads to violent crimes? Can super male syndrome be prevented?

01. What is super male syndrome?

Super male syndrome, also known as XYY syndrome, is a disease in which males have an extra Y chromosome than normal people. In addition to possible bad temper, irritability and aggressive behavior, super male syndrome also has the following typical manifestations: tall stature, broad face, thick limbs, impaired language and learning ability, neurodevelopmental problems and related psychological disorders.

The term "super male syndrome" actually downplays the risk of chromosomal diseases, making people think that it is just "bad temper, irritability and aggressive behavior." In fact, there are greater risks, such as the risk of a series of health problems such as abnormal intelligence and neurodevelopment. This genetic disease should really be avoided as much as possible.

The reason why we rarely mention it is because there is really too little research on it. You have to admit that biology is a nascent discipline.

Therefore, I have always recommended that, when conditions permit, optimization strategies should be adopted as much as possible for cases of chromosomal structural variation (SV) (deletion, duplication, inversion, translocation), not to mention the risk of the entire chromosome.

02. The real explanation of “xx gene”

Nowadays, many people are familiar with the concept of genes, so we often say that someone has XX genes. In fact, strictly speaking, this is an imprecise biological concept.

Under normal circumstances, all humans have 20,000 to 30,000 genes, whether you are an African or an Indian. This is shared by all humans.

What really differentiates us is not the concept of genes, but specific sites on genes. In other words, when we say someone has XX gene, what it really means is that someone has a recognized mutation (SNP or something like that) on XX gene.

In other words, when we studied genetic diseases in high school, concepts such as Aa did not actually represent a gene, but often just a site.

On the other hand, you can also realize that a single point of variation can lead to huge consequences.

03. Every single site can matter

A single mutation could have a major impact. For example, some people find cilantro delicious and like to add it to their diet, while others find it unpalatable and tastes like soap.

However, the influence on whether to eat coriander is only one site.

Through screening of the population, researchers found that whether or not people like to eat coriander is actually related to genes. Specifically, it is related to an OR6A2 gene on human chromosome 11, which is one of the human olfactory receptors and is very sensitive to aldehyde compounds. Aldehydes are an important source of flavor in coriander. Specifically, it is a SNP Rs72921001. The variant of this site will cause you to think that coriander has a soapy taste. (p = 6.4 × 10−9, odds ratio 0.81 per A allele)

However, this site is just a point on OR6A2, equivalent to 1/7,954 of the OR6A2 gene; and the chromosome where the OR6A2 gene is located is chromosome 11, and there are more than 1,300 genes like OR6A2 on this chromosome; how long is this chromosome? 135Mb, which is 135 million base pairs long. Many diseases fall on this chromosome; not to mention that the human genome is 3 billion base pairs.

Similarly, the presence or absence of body odor was also found to be associated with certain loci. The famous oncogene BRCA family also had mutations in some loci that caused several times the increase in cancer.

Just think about it, if a mutation in just one locus can have such a big impact, what will happen if you suddenly have tens of thousands or even hundreds of millions of loci? No one can predict it because it is too complicated. Because of this, clinically, it is often not recommended to give birth to a baby with a chromosome-level mutation because the hidden risks behind it are too great.

Of course, you might ask, what if the person is fine? That depends on your luck. Although there are many new drugs or treatment measures, our current strategies for dealing with genetic diseases are still very limited, and they are often very expensive and require special targeted research and development.

04. Nature and nurture

Although we acknowledge that a person's current condition is the result of a combination of innate and acquired factors, for example, the fact that people's heights are rising steadily today is not because there have been major changes in the genes of Chinese people, but because our nutrition has improved.

However, it would naturally be better if the innate error rate or uncertainty rate could be reduced. Otherwise, it would be much more difficult to improve nutrition after birth for people with dwarfism.

Eriksson N , Wu S , CB Do, et al. A genetic variant nearolfactoryreceptor genes influences cilantro preference[J]. Flavour,1,1(2012-11-29), 2012, 1(1):22.