trisómiától

Trisomy is a type of aneuploidy, which is a condition where an individual has an abnormal number of chromosomes. Specifically, trisomy occurs when there are three copies of a particular chromosome instead of the usual two. This extra genetic material can lead to a variety of developmental and health issues, depending on which chromosome is affected.

The most common trisomy in live births is Trisomy 21, also known as Down syndrome. Individuals with Trisomy 21 have three copies of chromosome 21. Other well-known trisomies include Trisomy 18 (Edwards syndrome) and Trisomy 13 (Patau syndrome), which are generally associated with more severe health problems and lower survival rates. Trisomies can also occur with sex chromosomes, such as XXY (Klinefelter syndrome) in males or XXX (Triple X syndrome) in females, which may have less pronounced effects on physical development.

Trisomy typically arises due to a random error during cell division, specifically during the formation of egg or sperm cells. This error, called nondisjunction, causes a pair of chromosomes to fail to separate properly. While the exact causes are not fully understood, advanced maternal age is a known risk factor for some trisomies. Diagnosis can often be made prenatally through genetic screening tests or diagnostic tests like amniocentesis or chorionic villus sampling. After birth, genetic testing can confirm the diagnosis. Treatment focuses on managing the symptoms and health issues associated with the specific trisomy.