Why Is Genetic Testing Important for Fertility?

Genetic abnormalities can cause infertility. In men they can affect sperm production or how the sperm moves from the testicle to the semen.

Here are three common genetic tests related to male infertility.

1. Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Gene Mutations 

Men with congenital bilateral absence of the vas deferens (CBAVD), which is when both vas deferens do not develop, require a test to determine if they are a carrier for the cystic fibrosis gene. This does NOT mean that they have cystic fibrosis but being a carrier for an abnormal copy of this gene occurs in men who have CBAVD. The determination of whether or not you have vas deferens is made on physical exam. 

In the case of congenital bilateral absence of vas deferens (the vas deferens don’t develop), you and your partner should have genetic testing and counseling in case you are carriers of cystic fibrosis (CF) because genetic carriers of cystic fibrosis can pass this onto their children. 

2. Karyotype

This test analyzes all chromosomes to see if there are any extra or missing chromosomes. Extra chromosomes can cause problems with sperm production. An example is Klinefelter Syndrome (KS), in which a man has an extra sex chromosome: XXY instead of XY.

3. Y-Chromosome Microdeletions (YCMD)

If you have Y-chromosome deletions, they can cause problems with how your sperm form. There is a genetic test that can be done to determine whether your Y chromosome contains all the critical genetic elements necessary to make sperm. This is important because there are some genetic mutations of the Y chromosome that are not compatible with producing sperm.

If you have fewer than five million sperm per mL in your semen analysis, we will recommend karyotyping and Y-chromosome analysis.

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