**Question:** All are true about Down syndrome except:

A. Increased risk of autoimmune disorders
B. Lower incidence of type 2 diabetes
C. Higher risk of Alzheimer's disease
D. Lower risk of ischemic heart disease

**Core Concept:** Down syndrome is a genetic disorder caused by the presence of an additional copy of chromosome 21. This abnormal condition, also known as trisomy 21, results in characteristic physical and cognitive features.

**Why the Correct Answer is Right:** The correct answer (D) refers to a lower risk of ischemic heart disease in individuals with Down syndrome. This is a misconception as people with Down syndrome have an increased risk of developing heart problems, particularly congenital heart defects and atrial septal defects (ASDs). ASDs are a type of heart defect where there is an opening between the two upper heart chambers (atria) and the two lower heart chambers (ventricles).

**Why Each Wrong Option is Incorrect:**

A. Increased risk of autoimmune disorders: People with Down syndrome are indeed at a higher risk of developing autoimmune disorders, which are conditions where the immune system mistakenly attacks the body's own tissues and organs. Examples include autoimmune thyroid disease, type 1 diabetes, and immune thrombocytopenic purpura (ITP).

B. Lower incidence of type 2 diabetes: Type 2 diabetes is primarily caused by insulin resistance and genetic factors, while Down syndrome is related to autoimmune dysfunction and insulin resistance. In contrast to the statement, people with Down syndrome have a higher risk of developing type 2 diabetes.

C. Higher risk of Alzheimer's disease: People with Down syndrome have an increased risk of developing Alzheimer's disease, a neurodegenerative disorder characterized by progressive memory loss and cognitive decline. The presence of the extra chromosome 21 contributes to the development of Alzheimer's disease in these individuals.

**Clinical Pearl:** Down syndrome patients are typically managed with a combination of supportive care, medications, and interventions to manage symptoms and complications. Adequate surveillance, early diagnosis, and appropriate interventions can help improve the quality of life and life expectancy of individuals with Down syndrome.