Your diagnosis
Monogenic hereditary diseases are those caused by alterations in the DNA sequence of a single gene. Although individuals with monogenic hereditary diseases do not necessarily experience infertility problems, they are advised to undergo in vitro fertilization (IVF) to analyze the embryos and select healthy ones for transfer to the uterus.
Genes are small segments of DNA. They are arranged in order on chromosomes within the nucleus of cells. Each cell has 23 pairs of chromosomes; two of them, the X and Y, are the sex chromosomes and determine sex; the remaining chromosomes are called autosomal chromosomes.
All genes serve as a template for the production of different proteins and together provide the information necessary to structure the body and its functions. When one of them is abnormal, it can produce an abnormal protein or produce abnormal amounts of protein that disrupt these functions.
Abnormal inherited traits do not always have health consequences; Sometimes the consequences are minimal, but they can also produce alterations that lead to a significant decrease in quality of life. Hereditary diseases affect 1-2% of the general population.
There are different patterns of single-gene inheritance:
A person only needs to receive the defective gene from one parent to inherit the disease. In these cases, the abnormalities generally appear in every generation, and each affected child has an equally affected parent. Unaffected individuals do not transmit the disease. When one parent is affected, the child has a 50% chance of inheriting the disease. Furthermore, men and women have an equal chance of suffering from it.
For example: Neurofibromatosis type 1.
Only individuals who inherit both copies of the affected gene (from their mother and father) will inherit the disease. Individuals with only one affected gene will be carriers of the disease, but will not express it.
For example: Cystic fibrosis.
X-linked dominant traits are rare. They occur in women who have a mutation in one of the two copies of the gene on the X chromosome, and in men who have the mutated gene on the only X chromosome they have. Both sons and daughters of an affected mother have a 50% chance of being affected, although the disease is generally milder in women than in men. Affected men only transmit the disease to their daughters; their sons will be healthy.
For example: Hypophosphatemic rickets.
In these cases, even if the woman is a carrier of an abnormal gene, she will not develop the disease because her normal X chromosome compensates for the abnormality. However, any male who receives the abnormal X chromosome will develop the disease. Every male child born to a woman who is a carrier of an X-linked recessive disease has a 50% chance of inheriting the defective gene and therefore developing the disease. Each daughter has a 50% chance of inheriting the defective gene and becoming a carrier of the disease. Carriers generally do not show symptoms of the disease, but may have an affected son. A man with an X-linked disease cannot pass the disease on to his sons because he provides them with the Y chromosome, but he will pass it on to all his daughters, who will be carriers.
For example: Hemophilia
Only males will suffer from a Y-linked disease. Therefore, an affected male will pass the disease on to all his sons, but not to any of his daughters. This type of inheritance is very rare.
Couples who are carriers of a monogenic hereditary disease have a high risk of transmitting this condition to their offspring and therefore have few reproductive options. Until now, they could opt for adoption, IVF treatment with sperm or egg donors, or conceive a child with the disease and opt for a therapeutic abortion. Preimplantation Genetic Testing (PGT) offers the possibility of having a child without transmitting the genetic disease. For couples at risk of transmitting a monogenic hereditary disease, PGT provides information on the status of each conceived embryo and allows only healthy ones to be transferred to the mother's uterus.
More information about
At Institut Marquès we have all Assisted Reproduction treatments in which we use the most advanced technology.
More information about
We finance all your Assisted Reproduction treatments. Calculate it yourself with our new financing calculator.
More information about
We are different from other centers: restless professionals who constantly seek improvement and excellence.
One of our team members will be in touch shortly through your preferred method of communication.
Fill out the form and we will contact you to arrange a visit with a specialist in Assisted Reproduction.
