All are true about Down syndrome except:
**Question:** All are true about Down syndrome except:
A. Increased risk of leukemia
B. Delayed bone age
C. Increased risk of thyroid disorders
D. Increased risk of autoimmune disorders
**Core Concept:** Down syndrome is a genetic disorder caused by the presence of an additional copy of chromosome 21. This results in a range of developmental and physiological challenges, including cognitive disabilities and distinctive facial features. Individuals with Down syndrome have an increased risk of specific medical conditions due to the genetic abnormality.
**Why the Correct Answer is Right:** The correct answer, **D**. Increased risk of autoimmune disorders, is not a unique characteristic of Down syndrome. Autoimmune disorders affect multiple individuals, regardless of whether they have Down syndrome or not. In contrast, the other options are directly related to Down syndrome's genetic abnormality.
**Why Each Wrong Option is Incorrect:**
A. Increased risk of leukemia: Individuals with Down syndrome have a higher risk of developing acute lymphoblastic leukemia. This increased risk is not a general characteristic of autoimmune disorders.
B. Delayed bone age: Down syndrome is associated with a delay in bone age due to the influence of the chromosomal abnormality on the growth and maturation processes.
C. Increased risk of thyroid disorders: Individuals with Down syndrome have a higher prevalence of thyroid abnormalities, particularly thyroiditis and hypothyroidism. This option is consistent with the genetic abnormality affecting the individual.
**Correct Answer: D**. Increased risk of autoimmune disorders (Option D) is incorrect because autoimmune disorders are not unique to Down syndrome. While individuals with Down syndrome have an increased risk of specific medical conditions, including autoimmune disorders, the question was asking for a characteristic that is unique to Down syndrome. The other options are more directly related to the genetic abnormality and the associated medical challenges in individuals with Down syndrome.