What is the chromosomal disease?
There are two main groups:
Numerical disorders. It is called aneuploidy (an abnormal number of chromosomes) and occurs when an individual either is missing a chromosome from a pair or has more than two chromosomes of a pair (trisomy, tetrasomy, etc.). Most common: Down's syndrome (trisomy by 21st chromosome), Patau's syndrome (trisomy by 13th chromosome), Edwards' syndrome (trisomy by 18th chromosome) Structural abnormalities: when the chromosome's structure is altered.
What is the risk of delivering a baby with a chromosomal disease?
According to the data of the World Health Organization, chromosomal disorders are observed in 0.3% of all newborns, in 25% of all natural abortions and in 50-60% natural abortions at the first trimester of pregnancy.
It is well known that the risk of chromosomal diseases of a fetus increases with the woman’s age.
The probability of delivering a child with a chromosomal disease is assessed as follows:
At the age of 30 years as 1/385
At the age of 40 years as 1/63 (!)
At the age of 45 years as 1/19 (!!!)
Noninvasive prenatal testing (NIPT), sometimes called noninvasive prenatal screening (NIPS), is a method of determining the risk that the fetus will be born with certain genetic abnormalities. This testing analyzes small fragments of DNA that are circulating in a pregnant woman’s blood.
- Trisomy 21 (Down syndrome)
- Trisomy 18 (Edwards syndrome)
- Trisomy 13 (Patau syndrome)
DNA diagnosis of mitochondrial diseases
Mitochondria - is a double-membrane-bound organelle found in most eukaryotic organisms. Mitochondria generate most of the cell's supply of adenosine triphosphate (ATP), used as a source of chemical energy. A mitochondrion has thus termed the powerhouse of the cell.
Mitochondrial diseases are one of the most common inborn errors of metabolism, with a conservative estimated prevalence of approximately 1:5,000. Primary mitochondrial diseases are defined as disorders impacting the structure or function of the mitochondria as a result of either nuclear DNA (nDNA) or mitochondrial DNA (mtDNA) mutations.
The structure of mtDNA contains structural genes encoding polypeptides, genes of ribosomal, and transport RNA. Many of the structural genes encode proteins that are responsible for the functioning of the respiratory systems and resistance to antibiotics. MtDNA is inherited only through the maternal line and passes in the blood of women over the generations.
MtDNA mutations and how to analyze them?
MtDNA mutations occur for a variety of reasons, much more often than in the DNA. Cells and tissues can contain both mtDNA of the same type (homoplasmy) and a combination of standard and mutant mtDNA in different ratios (heteroplasmy).
Recent researches have shown that mtDNA mutations also accelerate the aging process and the development of age-related pathologies, for example, neurodegenerative diseases. Besides, they can decrease male fertility, increase the risk of miscarriage during pregnancy and fetal disorders. Reducing the number of copies of mtDNA molecules also leads to the development of diseases such as myopathy, nephropathy, liver failure, etc.
PCR analysis stands for 'polymerase chain reaction. It is a technique that allows technicians to create millions of precise DNA replications from a single sample of DNA. It is also used in the early stages of processing DNA for sequencing, for detecting the presence or absence of a gene to help identify pathogens during infection, and when generating forensic DNA profiles from tiny samples of DNA.
Molecular genetic diagnostic
The "Medical Center IGR" performs a wide range of DNA testing of the most common monogenic disease. DNA test allows you to accurately identify the cause of the disease and make the correct diagnosis. The DNA analysis also makes it possible to establish kinship between family members (for example, paternity) even for the unborn child.
IGR Medical Center offers DNA diagnosis of...
- hemophilia A
- Duchenne muscular dystrophy
- Spinal Muscular Atrophy (SMA)
- heterozygous carriage of SMA
- hereditary hemochromatosis (HHC)
- Charcot–Marie–Tooth disease (CMT)
- Huntington chorea
- Prader-Willi and Angelman syndrome
- congenital adrenogenital syndrome
- Martin Bell-Renpenning syndrome or X-linked mental retardation
- premature ovarian failure or primary ovarian insufficiency
The advantage of diagnosing in the Medical Center of the IGR is the ability to determine the diseases on various biological material:
- Sex cells (polar bodies of oocytes, spermatozoa);
- Early preimplantation embryos (blastomeres, trophectoderm);
- Early prenatal diagnosis on chorionic villi (from 8 weeks of gestation);
- Amniotic fluid (from 16 weeks of gestation);
- The placenta (from the 12th week of pregnancy);
- Cord blood (from the 20th week of pregnancy);
- Venous blood (newborns, adults).