During a couple’s fertility evaluation it is important to consider genetic causes of male-factor infertility. Two of the most common genetic disorders that affect fertility are chromosomal irregularities that result in impaired testicular function and Y-Chromosome Microdeletions (YCM) that result in impaired sperm production. Because genetic disorders affect so many infertile couples, it is prudent to perform genetic testing prior to pregnancy, especially if a semen analysis indicates you have a sperm concentration of less than 5 million sperm per mL.
Klinefelter Syndrome
Most infertile males with chromosomal abnormalities have Klinefelter Syndrome, which means they were born with an extra copy of the X chromosome. This common genetic disorder often goes undiagnosed until adulthood, as it offers few noticeable signs such as smaller-than-normal size testicles, decreased muscle mass and decreased hair growth. Due to the testicles’ smaller size, sperm and testosterone production are diminished. A male born with Klinefelter Syndrome is expected to produce little to no sperm.
Klinefelter Syndrome is not inherited, but rather it is a random error that is diagnosed in the following ways:
Hormone Testing
Blood tests may uncover abnormal hormone levels that are a sign of Klinefelter syndrome.
Chromosome Analysis
A blood test called a karyotype (chromosome) analysis is used to check the shape and number of chromosomes. Males should have one X and one Y chromosome and females should have two X chromosomes. Klinefelter Syndrome is diagnosed when a male’s karyotype analysis shows he has two X chromosomes and one Y chromosome.
Most men with Klinefelter Syndrome are unable to father children. However, some do have minimal sperm production, which allows for sperm retrieval and in vitro fertilization (IVF).
Y-Chromosome Microdeletions
The Y chromosome is responsible for male sexual characteristics, including development of a man’s genitals, sperm development, and initiating changes that occur during puberty. Y-Chromosome Microdeletions (YCM), or missing portions of the Y chromosome, generally occur along the long arm of the chromosome and can affect sperm production. Depending on where the deletion(s) occur along the chromosome, you may have sperm in your ejaculate, sperm in your testicles but not your ejaculate, or no sperm at all. Genetic testing prior to pregnancy can pinpoint any YCM, giving your Inovi fertility specialist the information needed to proceed with the right fertility treatment.
Cystic Fibrosis Genetics
Men who have been diagnosed with Congenital Bilateral Absence of the Vas Deferens (CBAVD) can be expected to have an abnormality of the cystic fibrosis trans-membrane conductance regulator (CFTR) gene. This disorder is especially important to note, as it increases your risk of conceiving a child with cystic fibrosis. The risk cannot be fully realized until your female partner has genetic testing prior to pregnancy.
Genetic Testing Prior to Pregnancy
Though no longer required to get a marriage license in most states, genetic testing of two partners likely to start a family in the future is a good idea. A simple blood or saliva test called carrier screening (performed in a doctor’s office or with an at-home kit) can uncover any unknown conditions that will affect fertility and/or future children. If one partner is a carrier of an abnormal gene, it usually isn’t passed on unless his/her partner also has the same abnormal gene. That’s why it’s important for both partners to be tested.
Tests can evaluate genes for several hundred disorders and inform you of risks associated with passing them on. Though genetic testing cannot determine with 100% certainty whether your child(ren) will have a certain disorder, it can give you important information to consider when planning your family. If you have prior testing or a family history that suggests you and your partner may be at risk for having an affected child, you may benefit from undergoing In Vitro Fertilization with Preimplantation Genetic Testing. This process may allow you to conceive a healthy child and avoid the passing on the abnormal gene. You should make an appointment with your Inovi fertility specialist prior to discuss your options prior to conceiving.