The pattern of inheritance of retinitis pigmentosa are all Except
**Core Concept**
Retinitis pigmentosa (RP) is a group of genetic disorders characterized by progressive degeneration of the retina, leading to night blindness, loss of peripheral vision, and eventually blindness. The pattern of inheritance of RP can be autosomal dominant, autosomal recessive, X-linked dominant, or X-linked recessive.
**Why the Correct Answer is Right**
The correct answer is related to the pattern of inheritance of RP. RP can exhibit different modes of inheritance, including autosomal dominant (AD), autosomal recessive (AR), X-linked dominant (XD), and X-linked recessive (XR). Each pattern of inheritance is associated with specific genetic mutations and has distinct clinical features.
**Why Each Wrong Option is Incorrect**
**Option A:**
This option is incorrect because RP can indeed exhibit an autosomal dominant pattern of inheritance, where a single copy of the mutated gene is sufficient to cause the disease.
**Option B:**
This option is incorrect because RP can also exhibit an autosomal recessive pattern of inheritance, where an individual must inherit two copies of the mutated gene (one from each parent) to express the disease.
**Option C:**
This option is incorrect because RP can exhibit an X-linked dominant pattern of inheritance, where a single copy of the mutated gene on the X chromosome is sufficient to cause the disease, typically affecting females.
**Option D:**
This option is incorrect because RP can exhibit an X-linked recessive pattern of inheritance, where the mutated gene is located on the X chromosome and affects males, who have only one X chromosome.
**Clinical Pearl / High-Yield Fact**
A key aspect of RP is its genetic heterogeneity, with over 70 genes identified as contributing to the disease. Understanding the pattern of inheritance is crucial for genetic counseling and family screening.
**Correct Answer:** A, B, C, D. All patterns of inheritance are characteristics of retinitis pigmentosa.