Birth of a child – the happiest event for every married couple. Waiting for a meeting with a baby is often overshadowed by disturbing thoughts about his health and proper development.
In most cases, the alarms of young parents turn out to be in vain, but at times fate treats the unborn child quite severely: the kid receives not only the hair color, the eye section and a sweet smile from the mom and dad, but also various hereditary diseases.
According to medical statistics, the probability of a child with a hereditary pathology for each future mother is 3-5%. For example, the probability of having children with Down syndrome is 1: 700.
The most difficult to diagnose and give in to further treatment are rare, so-called orphan diseases: imperfect osteogenesis, bullous epidermolysis, Menkes syndrome, progeria and many others. As a rule, these gene hereditary diseases pose a threat to the life of the child, significantly reduce its duration and quality, lead to the onset of disability.
In our country, rare diseases are considered to occur at a frequency of 1: 10000.
Each cell of the human body carries a certain code embedded in the chromosomes. In total, there are 46 of them: 22 of them are autosomal, and the 23rd pair of chromosomes is responsible for the sex of the person. Chromosomes, in turn, consist of many genes that carry information about a certain property of the organism.
The very first cell, formed during conception, contains 23 maternal chromosomes and the same number of paternal. Defective gene or chromosome and leads to the occurrence of genetic disorders.
There are different types of genetic disorders: a defect of one gene, a chromosome defect and a complex defect.
Defect of one gene can be transmitted from one or both parents. And, being a carrier of a recessive gene, mom and dad may not even know about their disease.
These diseases include progeria, Menkes syndrome, bullous epidermolysis, imperfect osteogenesis. A defect transmitted from a chromosome of 23 sex pairs is called X-linked. Each person inherits from his mother an X chromosome, but from his father he can get a Y-chromosome (in this case a boy is born) or an X-chromosome (a girl appears).
If a defective gene is found on the X chromosome of the boy, it can not be balanced by a second healthy X chromosome, and therefore the probability of a pathology develops. This defect can be transmitted from the mother-carrier of the disease or formed completely unpredictably.
In addition, unlike the first trimester, abortion on such a long period is a extremely dangerous procedure for both the physical and mental health of women. The risk of spontaneous abortion after this study ranges from 0.5 to 1%.
With the help of the study of the chorion (tissue surrounding the fetus in the early pregnancy), it is also possible to identify genetic disorders in the fetus, including diagnosing fairly rare diseases such as bullous epidermolysis, imperfect osteogenesis. During this procedure, the doctor through the vagina inserts a thin tube into the woman's uterus. Pieces of chorionic villi are absorbed through the tube, and then sent for analysis.
This procedure is painless and can be performed as early as the 9th week of pregnancy, the results of the study will be ready in one to two days. Despite the obvious advantages, this procedure is not too much in demand because of the high risk of spontaneous abortions (2-3%) and various disorders of pregnancy.
Indications for the study of chorion and amniocentesis are:
- the age of the future mother is more than 35 years;
- chromosomal defects in one or both parents;
- birth of a child with a chromosomal defect in a married couple;
- future mothers, in whose families there were X-linked diseases.
If the studies have confirmed the existence of a genetic disorder, parents, having weighed all the Pros and Cons, need to make perhaps the most difficult choice in their lives: to preserve or terminate pregnancy, since the treatment of hereditary diseases in this stage, unfortunately, is impossible.
Diagnosis after childbirth
Diagnosis of rare genetic hereditary diseases can be made on the basis of laboratory studies. For several years in all maternity hospitals on the fifth day after the birth of the baby, newborns are screened, during which a number of rare hereditary diseases are diagnosed: phenylketonuria, hypothyroidism, cystic fibrosis, galactosemia and adreno-genital syndrome.
The rest of the diseases are diagnosed on the basis of symptoms and signs that can manifest themselves both during the newborn period and many years after birth. Symptoms of bullous epidermolysis and imperfect osteogenesis in most cases appear immediately after birth, and the diagnosis of progeria is most often put only on 2-3 years of the child's life.
It is very difficult for an ordinary pediatrician to recognize rare diseases, a physician may simply not notice their symptoms during normal reception. That's why Mom needs to be very careful with her own child and pay attention to the menacing signs: age-related motor skills, the appearance of seizures, insufficient weight gain, unnatural color and odor of feces.