Sperm genetic testing helps identify specific genetic issues that may contribute to male fertility problems. Genetic tests can help evaluate for sperm DNA fragmentation, chromosome aneuploidy and other genetic disorders that may interfere with successful fertilization or cause miscarriage.
DNA fragmentation in sperm occurs when the body is unable to repair breaks that occur in DNA and when there is a deficiency of proteins that typically bind DNA sperm genetic testing and keep it in a compact form that is less susceptible to damage. Fragmentation is a common cause of fertility problems in men. It can cause chromosomal abnormalities in the developing embryo, which can lead to pregnancy failure or recurrent miscarriage. DNA fragmentation can also result in low sperm count or poor sperm quality.
There are many things that can cause sperm DNA fragmentation, including age, smoking and drinking alcohol, environmental toxins, certain medical conditions and medications, urinary tract infections, varicoceles, and genetic disorders. High levels of sperm DNA fragmentation are also associated with recurrent miscarriage in women who undergo fertility treatments such as in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).
The two most common sperm DNA fragmentation tests used by doctors to assess the integrity of a sperm sample are the TUNEL test and the alkaline Comet test. Both are noninvasive assays that detect pre-existing DNA breaks in a sperm sample. They can detect both single-stranded (SS) and double-stranded DNA breaks (DS-DBs).
Although the predictive value of sperm DNA tests in routine clinical settings is limited, these assays can be useful to assist in the diagnosis of a number of underlying causes of fertility issues, such as defective chromatin remodelling, oxidative stress, subclinical infections, constitutive genetic conditions and genomic modifications such as telomere shortening.
Another genetic test that can be used to assess a sperm sample is the karyotype, which analyzes the number and structure of a man’s chromosomes. The karyotype can detect several types of genetic conditions that are known to cause fertility issues in men, including Klinefelter syndrome and Y chromosome deletions. It can also detect mutations in the gene that causes cystic fibrosis, which can cause an absent vas deferens and impair sperm flow.
Depending on the results of the genetic tests, doctors can develop a treatment plan for the patient that may include lifestyle changes, medication or supplements to improve sperm health and increase chances of a successful pregnancy. Alternatively, they can recommend other fertility treatments such as IVF with ICSI or sperm donation. If no genetic cause is found, a further diagnostic effort can be made to evaluate for less-common sources of male infertility, such as Celiac disease or problems caused by previous surgeries in the pelvic area. The most important thing is to talk with a doctor who has experience in performing and interpreting these and other genetic tests. This can ensure that the best possible treatment options are recommended for the couple.