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Genetic factors

It is believed that human chromosomes carry around 22,000 to 23,000 genes. An error in just one of these genes, sometimes just a single exchange in the building blocks of our DNA can, under certain circumstances, cause a serious illness. Genetic tests are often difficult to understand. It is therefore the task of a genetic counsellor to explain the findings to you in a simple and understandable manner.

Genetic factors in men

  • AZF deletion: parts of the Y chromosome are missing in the male genome. This is suspected when the semen analysis shows a very low sperm concentration (less than 1 million sperm per millilitre)
  • Cystic fibrosis: is a disease of the lungs and pancreas. It has been scientifically proven that the children of men with severe oligozoospermia (less than 5 million sperm cells per millilitre) or azoospermia have a significantly higher risk of developing cystic fibrosis.
  • Klinefelter Syndrome: men with this syndrome have one X chromosome too many (XXY), which leads to a reduction in the release of male hormones and a reduced quality of sperm, often even to a complete loss of sperm production. Such a disorder can only be treated with the aid of intracytoplasmic sperm injection (ICSI). If there is a complete failure to produce sperm, donor sperm would have to be used.

Genetic factors in women

  • In addition to chromosomal disorders, premature ovarian failure (POF) can be the cause of infertility in women. This means the cessation of ovarian function before the age of 40. There are many reasons for this, but genetic factors are known to play a central role. Women with POF can be carriers of what is known as a mutation in the fragile X syndrome gene (FMR1 gene). Cases of premature ovarian failure have also been described in triple X syndrome.
  • Furthermore, genetic changes in the FSH receptor can also be associated with premature ovarian failure. In the ovaries, the FSH receptor is necessary for follicular development. In the instance of infertility and primary ovarian failure, the genetic causes should always be considered. This is particularly important for carries of a premutation of the fragile X syndrome, since in the event of pregnancy they have a significantly increased risk (up to 50%) of having a child with pronounced fragile X syndrome. 

Dr Leonhard Loimer holds an ÖÄK diploma for genetics, which covers the basics of human genetics, family tree analysis, genetics in paediatrics, neoplasms and tumour predisposition, care of patients with genetic mutations and their families, epidemiology and law and ethics. He will be happy to provide you with comprehensive advice.