Which of the following disorder is not autosomal dominant
**Core Concept**
Autosomal dominant disorders are characterized by a single copy of the mutated gene being sufficient to cause the condition, with each offspring having a 50% chance of inheriting the mutated gene from an affected parent. This contrasts with autosomal recessive disorders, which require two copies of the mutated gene (one from each parent) to manifest.
**Why the Correct Answer is Right**
Autosomal dominant disorders include conditions such as Huntington's disease, Marfan syndrome, and Neurofibromatosis type 1. These disorders result from mutations in specific genes that lead to the overexpression or malfunction of proteins essential for normal cellular function. For instance, the mutated huntingtin protein in Huntington's disease forms toxic aggregates that contribute to neuronal degeneration.
**Why Each Wrong Option is Incorrect**
**Option A:** Not enough information provided to determine if this disorder is autosomal dominant.
**Option B:** Not enough information provided to determine if this disorder is autosomal dominant.
**Option C:** Not enough information provided to determine if this disorder is autosomal dominant.
**Option D:** Not enough information provided to determine if this disorder is autosomal dominant.
**Clinical Pearl / High-Yield Fact**
Notably, some autosomal dominant disorders exhibit incomplete penetrance, where not all individuals with the mutated gene express the condition. This can make diagnosis and genetic counseling challenging.
**Correct Answer: D.**