Fertility and Genetic Testing
Testicular mapping and genetic tests like the cystic fibrosis test, karyotyping and Y microdeletion analysis are important male infertility diagnosis tests for couples who are at risk of inherited genetic diseases. Dr. Bastuba will review the findings obtained from the tests and exams, discuss them with the male patient, and make a diagnosis about whether your infertility is due to a treatable cause or due to an unknown cause.
Genetic testing is one of the most rapidly expanding areas within the treatment of male infertility. Following the human genome project this explosive area of research has taken on new prominence and direction. There are three genetic tests that are most commonly used in the infertile male. If any of these tests are positive, Dr. Bastuba will walk you through your fertility options and recommend visiting with a genetic counselor.
Karyotyping looks at the big picture of genes. The chromosomes from a cell are literally laid out on a photograph plate and a picture is taken of them. This picture allows for visual confirmation that all the big pieces of genes are present. It looks for large changes, which can be present in up to 10% of males with very low sperm present.
How this might help you as a couple
The most common syndrome that could be found with karyotyping would be Klinefelter’s. The sperm is sometimes retrievable in patients with this genetic disease. It is important that the couple be aware of this as a possibility before moving forward. Some couples choose not to undergo karyotyping since they feel that these types of changes would not influence their decision of having children. This information however, allows couples to make informed decisions.
- Y microdeletion analysis can be useful in patients with no sperm in their ejaculate since certain microdeletions make it very unlikely to find any sperm within the testicle. Y chromosomal microdeletions at the azoospermia factor regions have been identified as one cause of unknown male infertility. With advanced infertility treatments such as intracytoplasmic sperm injection (ICSI), the increasing risk of male children genetically inheriting the Y microdeletion makes testing important for the future parents.
More than 10 million individuals have cystic fibrosis, without showing any symptoms. A DNA test from a blood sample, or tissue sample (by swabbing the inside of your cheek) can reveal if the male is a carrier or not. If both the male and female partner are carriers, there is a 25% chance that their child will have cystic fibrosis.
With testicular mapping, a non-surgical technique, we can detect sperm in the testicles of men who have poor sperm production such as non-obstructive azoospermia. Many men who have been diagnosed with non-obstructive azoospermia either due to hypospermatogenesis, maturation arrest or Sertoli-cell only syndrome (germinal cell aplasia) have been found to have small "pockets" of sperm production within the testicles. With testicular mapping, sperm production has been found in up to 70% of men who have FSH (follicle stimulating hormone) levels greater than three times normal or who had no sperm production on a past biopsy. Testicular mapping gives males a better chance of having a child because with assisted reproductive techniques such as IVF with ICSI, the requirements for sperm have been reduced to 1 live sperm per egg.