Following are examples of mitochondrial inheritance except:
**Core Concept**
Mitochondrial inheritance refers to the phenomenon where diseases or traits are inherited solely through the mitochondrial DNA (mtDNA). Mitochondria are the powerhouses of the cell, responsible for generating most of the cell's supply of adenosine triphosphate (ATP). Mitochondrial DNA is separate from the nuclear DNA and is inherited maternally, as only egg cells contribute mitochondria to the developing zygote.
**Why the Correct Answer is Right**
Mitochondrial inheritance is characterized by conditions that affect the respiratory chain or other mitochondrial functions, leading to various clinical manifestations. These conditions are typically inherited in a maternal lineage, as only mothers pass on their mitochondria to their offspring. Some examples of mitochondrial inheritance include Kearns-Sayre syndrome, MELAS syndrome, and Leber's hereditary optic neuropathy.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided in the question, but if you're looking for examples of mitochondrial inheritance, you might consider Leber's hereditary optic neuropathy (LHON), which is a classic example. However, without the option, it's hard to comment.
**Option B:** Not enough information is given about this option to determine its accuracy.
**Option C:** Not enough information is given about this option to determine its accuracy.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that conditions caused by mitochondrial inheritance often present with symptoms related to energy metabolism, such as muscle weakness, fatigue, or visual disturbances. These conditions can be challenging to diagnose, as they may have non-specific symptoms or variable penetrance.
**Correct Answer:** D.