Boys are more likely to be affected by which genetic disorders –
**Core Concept**
Genetic disorders that affect sex chromosomes, particularly those with an excess of Y chromosome, are more common in males due to their XY sex chromosome configuration. This is because the Y chromosome has no homologous pair, making it more susceptible to mutations and deletions.
**Why the Correct Answer is Right**
The correct answer is related to the fact that many genetic disorders are X-linked recessive, meaning they are caused by mutations in genes on the X chromosome. Since males have only one X chromosome, a single mutation can cause the disorder, whereas females, who have two X chromosomes, would need two mutations to express the disorder. Examples of X-linked recessive disorders include hemophilia A and B, Duchenne muscular dystrophy, and Hunter syndrome.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a genetic disorder that is more common in males. While some autosomal dominant disorders may be more common in males, this is not a specific example.
**Option B:** This option is incorrect because Turner syndrome, a disorder caused by a missing or partially deleted X chromosome, is more common in females. Males with Turner syndrome are typically infertile.
**Option C:** This option is incorrect because Fragile X syndrome, a disorder caused by a mutation in the FMR1 gene on the X chromosome, is more common in males. However, this is an X-linked dominant disorder, not the most common type of genetic disorder that affects males.
**Option D:** This option is incorrect because it is too vague and does not specify a particular genetic disorder.
**Clinical Pearl / High-Yield Fact**
A classic example of an X-linked recessive disorder is hemophilia A, which affects approximately 1 in 5,000 males worldwide.
**Correct Answer: C. Fragile X syndrome.**