MONOGENIC/SINGLE GENE DISORDERS
While conditions like autism and cancer are the result of variants in a complex network of genes, many inherited disorders are typically caused by mutations in a single gene. Although these single gene disorders are relatively rare in the general population, certain factors put some individuals at higher risk of inheriting and passing down these conditions. Learn more about genetics and inheritance here.
In some cases, family history of a genetic disease increases the likelihood of a couple having an affected child. Parents may not be aware of their carrier status prior to genetic testing because they are asymptomatic. However, if you find you are a carrier of a genetic condition, there are options open to you. Preimplantation genetic testing with Previda®-DX is an important step in your IVF process that allows you to screen the embryo for a specific genetic condition prior to implantation.
Our DNA is contained in structures called chromosomes. The number of chromosomes an individual possesses is visualized as a karyotype. Translocations are chromosomal structural changes that occur during cell division. There are two types of translocations that have unique clinical outcomes: balanced and unbalanced.
A balanced translocation – also known as a reciprocal translocation – is an equal exchange of segments between two chromosomes with no loss or gain of DNA. Individuals with balanced translocations are sometimes called translocation carriers; they frequently live without health complications, although some experience fertility problems later in life.
Unbalanced translocations are events where chromosomes do not exchange segments equally and therefore result in loss or gain of DNA. It is common for a reciprocal translocation carrier to produce a high number of embryos with unbalanced translocations. Embryos with unbalanced translocations are typically unstable and result in miscarriage or a newborn with a developmental disorder. Translocations can also result in various types of cancer including Ewing’s sarcoma and some forms of leukemia.