What are the etiological factors associated with Down Syndrome?

What are the etiological factors associated with Down Syndrome?

• A. Incomplete dominance of chromosome 21
• B. Trisomy 21, translocation, and mosaic Down Syndrome
• C. Polygenic inheritance leading to various disorders
• D. Viral infections during pregnancy

Answer: (B)

The etiological factors associated with Down Syndrome primarily include trisomy 21, translocation, and mosaic Down Syndrome. Trisomy 21 is the most common form of Down Syndrome, occurring when there is an extra copy of chromosome 21 in the individual's cells, which leads to the characteristic physical and cognitive features associated with the condition. Translocation Down Syndrome occurs when a part of chromosome 21 attaches to another chromosome, which can also lead to the presence of extra genetic material from chromosome 21. Mosaic Down Syndrome is a less common form where individuals have a mix of normal and abnormal cells, with some cells having the typical two copies of chromosome 21 and others having three copies. These genetic anomalies are well-established as the primary causes of Down Syndrome, distinguishing them from other options where mechanisms such as incomplete dominance, polygenic inheritance, or viral infections during pregnancy do not specifically relate to the development of this genetic condition.

The etiological factors associated with Down Syndrome primarily include trisomy 21, translocation, and mosaic Down Syndrome. Trisomy 21 is the most common form of Down Syndrome, occurring when there is an extra copy of chromosome 21 in the individual's cells, which leads to the characteristic physical and cognitive features associated with the condition.

Translocation Down Syndrome occurs when a part of chromosome 21 attaches to another chromosome, which can also lead to the presence of extra genetic material from chromosome 21. Mosaic Down Syndrome is a less common form where individuals have a mix of normal and abnormal cells, with some cells having the typical two copies of chromosome 21 and others having three copies.

These genetic anomalies are well-established as the primary causes of Down Syndrome, distinguishing them from other options where mechanisms such as incomplete dominance, polygenic inheritance, or viral infections during pregnancy do not specifically relate to the development of this genetic condition.