Around 15% of couples have difficulty conceiving. 50% of the time the problem lies with the man. In many cases, faulty genes are the root cause of the problem. But up until recently, there was no way of knowing what these genetic issues were. Cornell University researchers have now come up with a way to detect mutations in genes affecting fertility. Their findings were published in the Proceedings of the National Academy of Sciences. Common genetic variations are known as single nucleotide polymorphisms (SNPs). Every SNP affects a specific nucleotide or building block of DNA. Researchers say patients struggling with infertility can have their DNA sequenced. If doctors can figure out which SNP is defective, they can provide a genetic diagnosis. This may someday lead to intervention on the genetic level. Fertility specialists could simply detect faulty SNP’s and repair or replace them.
To locate the SNP causing the problem today, the genomes of healthy people are placed side-by-side with those having fertility problems, to locate where differences occur. But this method has been ineffective so far. There are too many genes responsible for fertilization, and the process is too complex. John Schimenti the director of the Center for Vertebrate Genomics along with Priti Singh, a postdoctoral fellow in Schimeti’s department, came up with this new method. These researchers used laboratory mice. They looked at a database of all known mice genes responsible for infertility. These have been arrived upon through testing which is not possible in humans. Then these genes were compared to genetic variation within the human genome. They found SNPs associated within four different genes that are thought to cause fertility problems in our species. Then these SNPs were tested in mice. Through this practice, researchers are beginning to identify those SNPs that cause human infertility. Though this genetic testing is not available yet, couples trying for six months to a year without conceiving should consult a physician. Both partners should be tested. Men should see an urologist or fertility specialist.