GENETIC TESTING: CLARIFICATION OF INFERTILITY
Chromosomes or genetic defects are not always visible, and many people are not aware they are affected. However, the presence of a chromosomal or genetic defect can be the cause of infertility, recurrent miscarriage or defects in the child.
At the Institut Dr Loimer in Linz, we recommend that every couple have their chromosome structure examined by karyogram and, if necessary, genetic counselling. Genetic testing is absolutely necessary if:
- the man or woman have, or are suspected of having a genetic disease, malformation or disability
- a genetic disease, malformation or disability has occurred in the family
- the couple who wish to have children are related
- there have already been repeated miscarriages or failed attempts at IVF
Balanced and unbalanced chromosome translocation
The most common genetic cause of an unfulfilled desire to have children is the change in the chromosomes: in three out of one hundred couples, a deviation is found in the man or woman, known as a balanced chromosome translocation. This means that when the cell nuclei are examined, pairs of chromosomes are found in which small sections are mutually exchanged (translocation). There are no consequences for the physical and mental health for the concerned patient.
The situation is different, however, if the man or woman with a translocation would like to have a child together, because the fusion of the egg or sperm cells and the associated division of chromosomes can lead to incorrect combinations (unbalanced translocation).
Mutations in genes
In order to diagnose changes in gene sequences, molecular genetic examinations are necessary.
Here are some of the parameters that may need to be clarified in the couple who wish to have children:
- Fragile X for premature ovarian failure of the ovaries (POF)
- AZF a,b,c in azoospermia or the inability of the sperm to attach to egg cells and penetrate them
- CFTR in suspected carriers of cystic fibrosis
- CYP21A2 for hormonal disorders