Monogenic/Single Gene Disorders (PGT-M) &
Chromosomal Structural Rearrangements (PGT-SR)
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.