mtDNAassociated Leigh syndrome affects the brain of afflicte

mtDNA-associated Leigh syndrome affects the brain of afflicted individuals and has an infantile onset. NARP (neurogenic muscle weakness, ataxia, and retinitis pigmentosa) has less severe symptoms with an onset in childhood. The same mtDNA mutation can cause both of these diseases. How can these differences in disease presentation, severity, and age of onset be explained for these two diseases?

Solution

Answer:

Leigh syndrome:

Symptoms are usually observed in infants, some individuals donot develoop symptoms until they become adult.

1) Severe neurological disorder

2) Psychomotor regression is observed

3) Dysphagia, vomiting and diarrhea are the symptoms observed.

4) involuntary muscle contractions,peripheral neuropathy and ataxia are common in this people.

5) hypertrophic cardiomyopathy

II)   NARP (neurogenic muscle weakness, ataxia, and retinitis pigmentosa)

This condition is observed in early childhood

1) It effects nervous system

2) Severe pain in arms and legs

3) Muscle weakness

4) Loss of vision, due to deterioration of retina

5) Dementia, loss in hearing, seizures and cardiac defects