Down syndrome is a congenital anomaly that is due to a trisomy (three copies, instead of two) of chromosome 21. Those affected by this syndrome may have intellectual disability and other complications. There are other trisomies that cause major complications in those who suffer, such as Edwards syndrome (trisomy of chromosome 18) and Patau syndrome (trisomy of chromosome 13).

Alterations in the number of sex chromosomes, known as sexual aneuploidies, can occur. Among the most common, Turner Syndrome (X0) and Klinefelter Syndrome (XXY) stand out. Those affected present, among other complications, problems of sterility and in the development of the sexual organs, and, in certain cases, intellectual disability. Down syndrome occurs approximately in 1/800 births.

Edwards Syndrome and Patau Syndrome appear in one of every 5,000 and 16,000 pregnancies, respectively. On the other hand, sexual aneuploidies affect in Turner Syndrome at 1/2500 and in Klinefelter Syndrome at 1/500 – 1/1000 births.

The incidence of these alterations increases with maternal age from the age of 35. This risk is determined in the first trimester of pregnancy, based on three factors: age of the pregnant woman, biochemical markers in maternal blood and abnormalities of the fetus appreciable by ultrasound.

There are also genetic syndromes that have their origin in the loss of small portions of the genome (called microdeletions). Those affected by these syndromes present at birth health problems that include malformations in various organs and intellectual disability. Unlike trisomies, these syndromes do not have a proven relationship with advanced maternal age.

In addition, it can report other uncommon chromosomal alterations such as trisomies 9, 16 and 22.

• Only 10ml of maternal blood is needed.
• This test can be performed from week 10 of pregnancy.
• This test is valid in patients receiving oocytes.
• This test can be used in twin pregnancies (for trisomies 21, 18 and 13).