A 10 years old female patient diagnosed as a case of down’s syndrome having mosaicism variety. The syndrome is usually associated with
**Core Concept**
Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of an extra copy of chromosome 21. In cases of mosaicism, the extra chromosome 21 is present in some but not all cells of the body, leading to variable expression of the syndrome.
**Why the Correct Answer is Right**
Mosaicism in Down's syndrome is associated with a lower risk of congenital heart defects and leukaemia compared to non-mosaicism. This is because the extra chromosome 21 is not present in all cells, potentially reducing the severity of the genetic effects. However, mosaicism does not eliminate the risk of intellectual disability, delayed speech, and other characteristic features of Down's syndrome.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not provide a specific association with Down's syndrome. While it is true that individuals with Down's syndrome are at increased risk of certain health problems, this option is too vague to be a correct answer.
**Option B:** This option is incorrect because it is not a characteristic association of Down's syndrome. While individuals with Down's syndrome may have a range of physical characteristics, this option does not specifically relate to the syndrome.
**Option C:** This option is incorrect because it is not a well-established association with Down's syndrome. While individuals with Down's syndrome may be at increased risk of certain health problems, this option is not a specific or well-documented characteristic of the syndrome.
**Clinical Pearl / High-Yield Fact**
It's essential to note that individuals with Down's syndrome, regardless of the presence of mosaicism, require regular health check-ups and monitoring for potential complications, such as hearing loss, vision problems, and thyroid disorders.
**Correct Answer: A. Mosaicism in Down's syndrome is associated with a lower risk of congenital heart defects and leukaemia.**