A 26-Year-Old Woman Is Being Evaluated for a Possible Inherited

question 13

Multiple Choice

A 26-year-old woman is being evaluated for a possible inherited disorder.  She has a 6-year history of generalized tonic-clonic seizures, and a year ago, she had partial loss of vision due to an occipital infarction.  Her mother has chronic intermittent muscle weakness and lactic acidosis, and her maternal uncle has hemiplegia.  Skeletal muscle biopsy of the patient shows ragged-appearing muscle fibers.  After further evaluation, all the affected family members are found to suffer from the same inherited disease.  Pedigree analysis is shown in the image below. Which of the following is the most likely explanation for the variability of clinical manifestations in the affected family members?

• A)Anticipation
• B)Heteroplasmy
• C)Incomplete penetrance
• D)Mosaicism
• E)Uniparental disomy

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Feels Hot

The sensation of experiencing an increase in body temperature or the perception of high environmental temperatures.

Acute Pain

A type of pain that is intense and of short duration, typically signaling tissue damage or other immediate health issues.

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A condition where an individual experiences challenges in taking in air, often feeling short of breath.