What is Genetic?
There are structures in the cells comprising human body called nucleus that are essentials for ensuring the functions run perfectly and ensuring the development of the body in healthy. These structures are called “genetic structure” . Diseases occurring because of changes in these structures are named “genetic diseases”.
What is the range of genetic diseases?
Compiling genetic disease under four subtitles is possible one of which is chromosome disease, the other is one-gene disease, yet another is multifactor diseases and the last one is mitochondrial diseases. Chromosome diseases are faced when the number of the structures (23 pairs= 46) change. One-gene diseases, their number now increases to 10.000, are occurring when the genetic structure changes, called mutation. Multifactor diseases are seen an interaction between genetic factors and environmental factors. Genetic diversions in mitochondria’s, existing out of the nucleus and being the source of energy for the cells named mitochondrial diseases.
To whom are genetic tests being done?
These tests are implemented babies having the risk of genetic, adolescences and adults, risky pregnant persons, some of couples wanting assistant breeding methods.
The situations offered genetic tests
At what stages genetic tests are put into practice?
What is Preimplantation genetic diagnosis (PGD)
In today’s world some of genetic diseases can be diagnosed at the stage of 3-4 months of pregnancy by using prenatal diagnosis techniques (CVS, amniocentesis and chordocentesis) and if any defect are found, the pregnancy is given an end. Developments followed in the last years make it easier to check embryos created via test tube baby. Called PGD this method is realized by 1-2 cells from embryos created by inseminating sperm and oocyte in the laboratory. These cells are checked by specific methods and chromosome defects and single gene disorders are diagnosed (Thalassaemia, Sickle Cell Anemia, Cystic Fibrosis).
To whom is genetic diagnosis subjected?
- Advanced maternal age (≥37)
- Recurrent pregnancy loss
- Couples suffering acute male infertility
- Recurrent implantation failures (?)
What is the goal of genetic diagnosis?
What are the advantages of preimplantation genetic diagnosis?
What are the genetic diagnosis methods?
What is genetic consultation and to whom it is offered?
Genetic consultation is to give information to the patients who are having a genetic disease or having a risk of a genetic disease, to their relatives regarding the advancement of the illness, treatment methods, the risk of recurring of the illness and solutions. The primary duty of consultants is to convey the correct information and to show people some solutions. Therefore genetic consultancy should never be in a way of directing the patients, contrarily all information should be given understandably and the decision should be given to them.
The situations which genetic consultancies are offered
What are offered those who made a marriage between relatives or will made marriage between relatives?
Marriage between relatives is a marriage realized between people who are having a blood-relation. The rate of that in Turkey is 21% and it is the highest rate in the world excluding e few isolated society. Generally 2-3 of every 100 babies in Turkey ( 2%) are faced some anomalies. The risk is multiplied by two in marriages between relatives (4-5%). If a couple has an autosomal recessive disease after their first baby, for other pregnancies the risk increase the percentage of 25. Hence these pregnancy should be followed closely and 2.level ultrasonography should be done. After the birth, some scanning tests must be realized against some disease like phenylketonuria. If some genetic diseases occur after the birth, couples must be warned for the next pregnancy and be offered to wait for another 2-3 years.
What are the points which older promising mothers should be careful in respect to genetic?
In advanced mother age (older than 35), the risk of chromosomal genetic disease increases and Down syndrome is often seen. Although down syndrome is seen in every 700-800 birth, it increases in proportion to the age of the mother and at the of 40-45 the rate chances 1-4%. For this reason to the mothers this risk should be told and genetic diagnosis should be offered.
What are offered to people who are suffering repetitive pregnancy loses?
There are different reasons causing abortion. The most important reason of it is chromosome anomalies connected to baby and these anomalies are responsible for 50%-60% for the first period (the first 3 months), 20%-25% for the second period and 5%-10% for the third period of the abortions. These anomalies in general are newly occurred ones and the risk is less for the successive pregnancies. However sometimes even if the couples is both healthy, some abortions can be seen because of chromosomal irregularities. Hence chromosome analysis should be done by getting blood samples obtained either baby or couples. If the tests turn no result, the other factors should be evaluated by a gynaecologist.
What is the role of genetic factors on infertility?
Nowadays almost 15% of couples have diminished infertility. Male infertility is mainly responsible and it is known that genetic diseases impair the sperm amount. Therefore if the reason of infertility is not diagnosed, some genetic tests should be offered their reasons should be told. After finding some genetic defects, The couples must be informed, the possible risks must be told and the process of pregnancy must be explained in detail.
To where people can apply to be able to have genetic tests?
Increasing number of the people suffering genetic diseases and especially the obligation of using many different tests for one-gene diseases make impossible to conduct all tests at just one medical center. Besides, even in today’s world there are many diseases that can not be known or diagnosed that make it also impossible to realize the tests.
