Extraction of genomic DNA from blood samples
Carrier screening involves analyzing the DNA we extract from the blood. Each sample of extracted DNA undergoes internal quality control.
Carrier Seq
Free delivery across Russia
30 000 ₽
Available on credit
Available on credit
Carrier Seq
A test to detect an abnormal copy of an altered gene in a person that leads to the development of a genetic disease.
Free delivery
From anywhere in Russia
417 genes
Extensive screening panel
Consulting
Free consultation with a geneticist
Up to 25 working days
Timeframe
What are the risks of a couple passing on a genetic disease to their child?
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Approximately 1 out of every 200[1] couples in the general population is at risk of being carriers of an inherited genetic disease[2].
Carrier is a person who has a genetic variation in their DNA associated with the disease and might pass it on to the next generation.
An inherited genetic disease is a pathological condition of the body caused by an abnormality in a certain gene. The result of the abnormality in the DNA can range from asymptomatic to serious life-threatening health issues.
1 из 200The incidence of hereditary diseases in newborns is 1 in 200 [4].
6000hereditary diseases have been identified to date [3].
With a seemingly low incidence of genetic diseases, an average incidence of carriage of altered genes in healthy population is 1 per 20-50 people.
All inherited diseases are caused by changes in a specific gene and are known as monogenic or Mendelian disorders.
Types and Prevalence:
- fermentopathies;
- hearing and sight defects;
- skeletal dysplasias;
- various forms of mental retardation;
- lesions of the nervous system, endocrine system, connective-tissue, etc.
With the development of molecular genetic technology, couples planning to have children can learn more about their future family's health than ever before.
In many cases, parents are unaware that they are carriers, have no family history or symptoms of the disease.
Carrier screening is an important tool to help parents-to-be determine the risk of having a child with an inherited disease.
How are genetic diseases inherited?
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Most families that have a child with an inherited disease usually have no family history of that disease and no awareness of the increased risks of having a child with a genetic abnormality.
Each person is a carrier of a large number of gene variants, some of which are pathogenic. Thus, if both spouses are carriers of a pathological variant in the same gene, there is a high probability of a child being born with an inherited disease.
Example
When both partners are carriers of abnormal variations in a gene associated with the development of cystic fibrosis, the probabilities of passing the gene are:
25%the probability of a child having the disease
50%the probability of a child being a carrier of a pathogenic variant in the cystic fibrosis gene
25%probability of a child inheriting two healthy genetic copies and not being a carrier
Autosomal recessive genetic disorder occurs when both partners are carriers of a pathological copy of a certain gene. This means that for the clinical manifestation of the disease, the child must inherit two abnormal copies of the same gene (one altered copy from each parent).
If both parents are carriers of an altered copy of the same gene, they can pass to their child both the normal copy and the "defective" copy.
There are two main types of inheritancethat can lead to a healthy couple having a child with a genetic disease:
Autosomal recessive type
Autosomal means that the defective gene is located on any of the chromosomes other than the sex chromosomes (X or Y).
In this type of inheritance, each parent has 1 "abnormal copy of the gene" and 1 normal/functional copy of the gene, so the disease does not manifest, and the person is reffered to as a "healthy carrier".
The disease develops when each of the carrier parents passes a "pathological copy of the gene" to their child.
When two healthy carriers have a child, the risk of that child being born sick is 25%.
Examples of diseases:
- hereditary metabolic diseases (cystic fibrosis, phenylketonuria, adrenogenital syndrome, galactosemia, congenital hypothyroidism)
- spinal muscular atrophy
- sensorineural hearing loss
X-linked recessive type of inheritance
Sex-linked diseases are associated with the presence of defective genes on the sex chromosomes (X or Y).
The disease develops if the associated gene is found on the X chromosome. And, since boys have only one X chromosome, one altered copy of the gene is enough for them to develop the disease.
Therefore, if the carrier mother passed on a "dysfunctional copy of the gene" to her son, he will develop the disease. Sons never inherit their father's disease because fathers pass on their Y chromosome.
If a woman is a carrier of a pathological copy of a gene associated with the development of X-linked recessive disease, she will pass on the altered gene to 50% of her children, regardless of gender.
In this case, the risk of giving birth to a son with a disease is 25%, while both daughters are healthy, and one of them is a healthy carrier of the abnormal copy of the gene.
If the father is sick, all of his daughters are healthy, but are healthy carriers of the pathological copy of the gene.
Examples of diseases:
- X-linked adrenoleukodystrophy
- hemophilia A, B
- Duchenne muscular dystrophy
Couples who are carriers of recessive diseases in most cases do not have any clinical manifestations, and, unfortunately, often find out about their genetic status only after the birth of a child that has inherited abnormal copies of the gene and shows clinical manifestations of a certain disease.
To prevent a family from having a child with an inherited genetic disease, it is essential to test for the carrier of at least the most common gene variations during the pregnancy planning stage.
Living with a genetic disease
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Common to most hereditary genetic diseases is a significant reduction in the life expectancy of patients.
The vast majority of hereditary diseases are known to most often begin to manifest at a young age. The first symptoms of some diseases do not appear immediately, but a year or even several years into the normal development of the child.
About 30%of children do not live to the age of 5 [5]
Genetic diseases are largely untreatable, with only symptomatic therapy aimed at addressing clinical manifestations.
For some diseases there now exist fundamentally new methods of treatment based on genotherapy. But the cost of treatment for patients with hereditary diseases is very high.
Example
Spinal muscular atrophy is a severe hereditary neuromuscular disease that progresses very quickly: patients first lose the ability to walk, then to eat and even breathe. Half of children with SMA do not live to be two years old. For a long time, SMA was considered incurable and the diagnosis was a death sentence. But now a medication called Zolgensma has been developed, an ampule of which costs about 154 million rubles.
Скрининг на носительство генетических изменений
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Carrier screening is genetic testing designed to detect an abnormal copy of an altered gene in a person that leads to the development of a genetic disease.
Indications: healthy couples who are planning a pregnancy and want to know their carrier status to assess the likelihood of having a child with a genetic disease.
Everyone is eligible for testing, regardless of the presence or absence of family history of a particular genetic disease.
If spouses are found to be carriers of abnormal changes in the same gene responsible for the development of a genetic disease, they are referred for genetic counseling.
The doctor can
- determine the type of inheritance of the disease,
- explain the significance of received information for the development and health of the future child
- help choose the most effective way to prevent the detected disease and give birth to a healthy child.
It is possible to use assisted reproductive technologies with preimplantation genetic diagnosis (PGD) (PGT-M) to select embryos that do not carry abnormal gene copies.
Carriers of hereditary diseases who have a high risk of having a sick child can use alternatives, such as sperm or egg donors.
This test evaluates the most frequent gene variations associated with genetic diseases in a single procedure. It allows to significantly reduce the risk of giving birth to children with hereditary pathologies.
Carrier testing is a once in a lifetime procedure for you and your partner.
However, if you are identified as a carrier of certain abnormal genes and there is a new partner, they are advised to get tested, but only for the genes in which you have been found to have changes.
Recently, more and more data indicate the high efficiency of next generation sequencing (NGS) methods for identifying the genetic cause of certain groups of inherited diseases.
In our laboratory, the test is performed on a certified and registered F-Genetics platform.
First Genetics' laboratory test allows for simultaneous disease risk assessment for 417 syndromes.
Basic steps of the test
Amplification
This step involves the amplification (accumulation) of strictly defined DNA regions considered most important for disease recognition by polymerase chain reaction (PCR). The DNA fragments synthesized in this reaction are called amplicons.
Ion Semiconductor Sequencing
We then sequence each nucleotide in all PCR-derived and quality-controlled amplicons by next-generation sequencing (NGS).
All amplicons are labeled with identical DNA adapters, which are special sequences required for simultaneous sequencing of many different DNA fragments.
Test result
Special software and computer algorithms are used to detect changes in the DNA sequence. The data obtained are then interpreted by comparing the results with databases that list variants associated with genetic diseases.
Additional Information
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Human genetic or hereditary material consists of a chemical called DNA (deoxyribonucleic acid). Each strand of DNA consists of four types of nucleotides (adenine, thymine, cytosine, and guanine).
All human hereditary information (the genome) consists of three billion pairs of nucleotides. Genes are small pieces of DNA that contain all the information about how our body functions. Genes in the human body come in pairs.
The human genome contains about 20000 active genes.
The human genome is packaged in 23 pairs of chromosomes: 22 pairs of autosomal chromosomes and a pair of X and Y sex chromosomes (XX in women, XY in men). Thus, human somatic cells have 46 chromosomes, each containing hundreds of genes.
The sperm and egg contain only half of the somatic cell chromosomes, that is, 23 chromosomes each. During fertilization, when the egg and sperm combine, the two sets of chromosomes form pairs. As a result, one half of the child's genetic material comes from the mother and the other half from the father.
Each person is a carrier of a number of gene changes.
Changes in genes are commonly referred to as genetic variations. As a result of these rearrangements, sometimes a defective copy of a gene cannot perform its functions as intended.
Often a person who has just one copy of a defective gene is unaware of its presence because a second, normal copy of the gene compensates the function of the altered section of DNA. In the vast majority of cases, they will be a "healthy carrier". If abnormal gene copies are located in germ cells, they are passed on to offspring.
A carrier is a person who has one abnormal copy of a gene that doesn't work correctly, while the other copy is normal. The carrier may have no symptoms of the disease or show mild clinical symptoms.
However, each carrier has the risk of passing on an abnormal copy of the gene to the next generation, and the child of a couple where both parents are carries a defective copy of the same gene may be born with an inherited disease.
- Carrier
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A person without signs of the disease, but who has a risk of passing on an abnormal copy of the gene to the next generation.
- Carrier screening
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A test to find out whether or not a healthy person is a carrier of a recessive genetic disease.
- DNA
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Genetic material that is passed from parents to children. DNA is packaged in structures called chromosomes.
- Chromosomes
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Structures inside each cell of an organism. Chromosomes contain genes.
- Gene
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A piece of DNA that contains instructions for the formation of certain human characteristics and traits, as well as for the control of body processes. A gene is the basic unit of heredity and can be passed from parent to child.
- Somatic cells
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The cells that make up the body (soma) of multicellular organisms and do not participate in sexual reproduction.
- Polymerase Chain Reaction (PCR)
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An experimental molecular biology method that allows significant amplification of small concentrations of certain nucleic acid (NK) fragments in biological material.
- DNA library
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A set of DNA fragments subjected to sequencing. These DNA fragments are labeled with identical DNA adapters, which are special sequences required for simultaneous sequencing of many different DNA fragments.
- Sequencing
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Determination of the nucleotide sequence in DNA. Comparing the DNA sequence in a sample to a standard human sequence allows to determine if there is an abnormality in the sample.
- NGS (Next-Generation Sequencing, high throughput sequencing)
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A sequencing technology in which the DNA sequence is simultaneously read for a large number of short segments. These segments are then assembled on a computer to create a complete picture. This technology makes it possible to examine not just a single segment of DNA, but large fragments or even the entire genome in a short period of time.
1. Xiao Q., Lauschke V. M. The prevalence, genetic complexity and population-specific founder effects of human autosomal recessive disorders // NPJ genomic medicine. — 2021. — Т. 6. — №. 1.— С. 1-7 — URL: https://www.nature.com/articles/s41525-021-00203-x
2. Ropers H. H. On the future of genetic risk assessment // Journal of community genetics. — 2012. — Т. 3. — №. 3. — С. 229-236
3. Wakap S. N. et al. Estimating cumulative point prevalence of rare diseases: analysis of the Orphanet database // European Journal of Human Genetics. — 2020. — Т. 28. — №. 2. — С. 165-173
4. Sateesh M. K. Bioethics and biosafety. — IK International Pvt Ltd, 2013
5. Angelis A., Tordrup D., Kanavos P. Socio-economic burden of rare diseases: a systematic review of cost of illness evidence // Health Policy. — 2015. — Т. 119. — №. 7. — С. 964-979
6. Novikov P. V. Legal aspects of rare (orphan) diseases in Russia and in the world //Medicine. - 2013. - T. 1. - №. 4. - p. 53-73
How do I get a DNA test for being a carrier of genetic diseases?
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Позвоните 8 (800) 201-74-63 and submit an application
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Оплатите исследование на сайте
Price 30 000 ₽
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Сдайте венозную кровь
Give blood (4 mL) in an EDTA tube (with a purple cap)
Be sure to sign each tube!
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Получите результат на эл. почту через 25 рабочих дней
DNA gene carrier test at First Genetics Laboratory
Specialists
Years of experience in genetics, laboratory diagnostics and bioinformatics
Confidentiality
All data is strictly confidential and cannot be passed on to third parties
Security
Extensive control at each stage of testing
Timeframe
Results ready in a short time
Free delivery
Free delivery of biomaterial across Russia
Carrier Seq
A test to confirm or refute the carrier of genetic diseases
Call us if you have any questions:
8 (800) 201 83 46
8 (800) 201 83 46
Genetic counseling
Specialized medical service for expectant parents, aimed at minimizing the likelihood of having a child with a hereditary pathology.