What is the most common mosaic trisomy detected through amniocentesis?

Mosaic trisomy 20 is indeed often reported as the most common mosaic trisomy identified in samples like those obtained from amniocentesis. This condition arises when there is a mix of normal and abnormal cells containing an extra chromosome 20. Unlike other trisomies that are more commonly associated with significant clinical features or developmental issues, mosaic trisomy 20 may not manifest serious clinical consequences, which can lead to higher detection rates during prenatal screenings without the same level of follow-up or concern seen with other trisomies.

Trisomy 21, which is also known as Down syndrome, is the most prevalent chromosomal abnormality leading to live births, but it is not typically labeled as mosaic when detected during amniocentesis. It has a well-characterized pattern of incidence and effects that make it more recognizable, often leading to a focus on complete trisomy rather than mosaic forms.

Similarly, trisomies 18 (Edwards syndrome) and 13 (Patau syndrome) are associated with more severe outcomes and lower survival rates. The detection of these trisomies often results in significant counseling around the implications for the pregnancy, which might influence the reported experiences of healthcare providers and patients. This makes them less represented as "