There are many diseases that are included in mitochondrial disorders. They often share common features.
Synonyms:
a.k.a. mitochondrial cytopathies, mitochondrial neurological disorders
Subtypes of mitochondrial disorders:
- Alper syndrome a.k.a. Alper-Huttenlocher syndrome a.k.a. progressive infantile poliodystrophy
- Kearns-Sayre Syndrome KSS
- Mitochondrial encephalomyopathy lactic acidosis and stroke MELAS
- Myoclonic epilepsy and ragged red fibres MERRF
- Mitochondrial neurogastrointestinal encephalomyopathy MNGIE a.k.a. MINGE
- Leber’s hereditary optic neuropathy plus dystonia
- Leigh’s disease a.k.a. Subacute necrotizing encephalomyelopathy
- Bilateral striatal necrosis
- Ziduvodine myopathy
Diagnosis:
Based on Genetics +muscle biopsy +clinical +other tests
Muscle biopsy:
False negatives can occur
HE: angulated atrophic fibres, subsarcolemmal granular appearance. GMT: ragged red fibres. COX: COX deficient fibres
EM: pleomorphic mitochondria, subsarcolemmal mitochondria
NCS/EMG: Axonal peripheral neuropathy
Findings on investigations:
OGTT: diabetes mellitus
Fundoscopy: retinitis pigmentosa
Lactic acid: increased
Abdominal X-ray: intestinal pseudoobstruction