In this age, when the human genome is deciphered, it’s hard not to be interested – how can this be applied in everyday life. But communication with a geneticist happens not only for those who are curious, but also for those who plan to give birth to a healthy child: often the first acquaintance with this doctor occurs during pregnancy.
About what the geneticist is doing, and what he can warn, Julia Vladimirovna Maksimova, head of the medical genetics NGMU, the main geneticist of the health department of the Novosibirsk region, told in an interview.
Interview with a geneticist about how to plan a pregnancy and know in advance the nature of a child
Why consult a geneticist, than this doctor can help a couple planning children?
Unfortunately, why a medical geneticist is needed and what he does, people do not always understand. Genetics usually fall in the direction of doctors of other specialties or absolutely accidentally, for example, a few days ago a man with a child came to me to ask how to find an allergist, and the child has a classic hereditary disease that can be put on the basis of signs on the face.
If you are examined before pregnancy, you can exclude chromosomal abnormalities from the parents or look at the main mutations in the genes of frequent monogenic diseases and try to prevent the pathology of their unborn child. There are so-called malformations of the fetus associated with the folate cycle.
We – the people of Siberia, and there is very little folic acid, which is in the green, we consume it catastrophically little – it is not enough even in European countries. So, if we take folic acid three months before the planned pregnancy, we reduce the probability of developing fetal malformations in the fetus.
On the territory of the FNL, there are about 400 congenital malformations of various genesis per 30 thousand children born per year, we do not differ drastically from other territories. There are successful programs to reduce the number of congenital malformations, but to zero their number will not be reduced for a very long time, since we are at the beginning of the path of cognition, and nature has been improving for millions of years.
What diseases can a geneticist predict?
It is generally believed that all diseases have a share of hereditary predisposition and everything depends on the size of this proportion. There are chromosomal diseases, they usually arise spontaneously. Changes in chromosomes occur in every 600th person. Monogenic diseases (they are known more than 4 thousand) are inherited in different ways. This is a defeat in a single gene, and a person has more than 30 thousand, so to “see” if there is a change, you need to know what gene there can be a defect, and to aim it straight. Unfortunately, while we can analyze less than a thousand changes in genes, clearly associated with a particular disease. But for five hereditary diseases (this is phenylketonuria, congenital hypothyroidism, cystic fibrosis, adrenogenital syndrome and galactosemia), a ministerial program for all newborns has been introduced.
Diseases with hereditary predisposition account for more than 90% of all human diseases. This includes both congenital malformations and chronic diseases. To assess the probability of such a disease in a particular person, today, except for the analysis of the genealogy, there are practically no methods, so the forecast can only be probabilistic.
And if a woman is already pregnant? Does it make sense to check it?
There are two types of prenatal diagnosis: standard and advanced. All pregnant women undergo ultrasound (at 11-13 weeks and 22-24 weeks) and biochemical screening. If any deviations are detected by these methods, the gynecologist recommends turning to the geneticist, who in turn decides whether to prescribe an extended examination in this case to reveal the chromosomal pathology in the fetus.
Biochemical screening is often called an analysis of “ugliness” or “down” – in fact, it does not allow you to say whether a child is healthy or not, this is only an excuse for further research. But some women are frightened of the name and avoid this survey.
It is very important to correctly pass this analysis, because in the end it allows you to calculate the risk for a child’s chromosomal disease. This car is considered a risk, and if the weight, age, or length of pregnancy on the day of the test is incorrectly laid, then the results change, in which only the specialist can understand. Therefore, it is not necessary to get upset prematurely, seeing in the given conclusion deviations from the written norm.
In fact, if the doctor finds a violation, the only way out is to terminate the pregnancy?
If we conducted an extensive examination of a pregnant woman and found a chromosomal pathology in the fetus, the woman is informed about this. And further each family decides the fate of this pregnancy independently and is not always unambiguous.
There is an opinion that in the risk group those who took alcohol at an early date, not knowing about their situation …
Alcohol initially is in our blood – a chemical substance that we produce. Man – as a small factory for the production of small doses of alcohol, and if some substance becomes larger, a compensatory mechanism that starts to utilize surpluses works – this mechanism is debugged and works for all. If alcohol was used in small doses, a catastrophe will not occur. It will happen, if the mother constantly, during the entire pregnancy takes alcohol – only then the child can form a specific alcoholic damage to the fetus. And smoking, even passive, affects the chromosomes, the genes of both the fetus and the mother, so smoking should be thrown not only to mom, but to others.
And the age of the future mother – how great is his role?
The probability of violations in the fetus increases with age in a woman, especially after 35 years, but this does not mean that the child will be necessarily sick. Such pregnant women just need a more extensive examination of the fetus. When a woman has a daughter, not only the fruit of the girl is formed inside, but also her eggs, and even if the baby was born healthy, it is not the fact that healthy children will be born with her. Late births began to spread in the 60-70s of the twentieth century in the West, there already have the first long-term results. The problem of primary infertility there is very acute.
Who needs to get to genetics?
Any woman after 35 if she is planning a pregnancy. Children with congenital malformations or often ill children, couples who can not become pregnant. If the family has several patients with one disease, for example, an early infarction. And … nobody canceled intuition. If you have an interest – this is already an indication, you are already interested and ready to make a choice; Whether you use this recommendation is another matter.
Is it true that by inheritance not only diseases are transmitted, but also character, some abilities?
What is temperament? In fact, this biochemical process, as it is laid – this will happen. For example, washing machines: some have a spin speed of 300 turns, others – 1000. The temperament affects the character, there is an opinion that 50% of the character is heredity, the second half is upbringing. The more complex a psychological act, the more it is conditioned by upbringing, life experience. The simpler – the more genetics there are, for example: the reaction rate (in you throw the ball, and you shy away), that is, the time from presentation of the stimulus to the moment of your reaction to it. This time does not train. You can improve the technique, but do not increase the speed.