One of the following disorders is due to maternal disomy of chromosome 15 –
**Core Concept**
The question is testing the understanding of **genetic disorders** caused by **abnormalities in chromosome inheritance**, specifically focusing on the concept of **uniparental disomy**. Uniparental disomy occurs when a person receives two copies of a chromosome, or part of a chromosome, from one parent and no copies from the other parent.
**Why the Correct Answer is Right**
The correct answer is related to **Prader-Willi syndrome (PWS)** or **Angelman syndrome**, which are associated with abnormalities in chromosome 15. Specifically, **Prader-Willi syndrome** can be caused by **maternal uniparental disomy** of chromosome 15, where a person receives two copies of chromosome 15 from their mother and none from their father. However, the more common cause of PWS is the deletion of a segment of the paternal chromosome 15.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a condition related to maternal disomy of chromosome 15.
**Option B:** Similarly, this option does not correctly identify a disorder caused by maternal disomy of chromosome 15.
**Option C:** This option is also incorrect as it does not relate to the specific genetic condition caused by maternal disomy of chromosome 15.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that **Prader-Willi syndrome** and **Angelman syndrome** are both associated with chromosome 15 abnormalities but have different clinical presentations and genetic causes. Prader-Willi syndrome is characterized by obesity, short stature, and intellectual disability, while Angelman syndrome is known for severe intellectual disability, speech impairment, and ataxia.
**Correct Answer:** Correct Answer: D. Prader-Willi syndrome