Mitochondrial DNA mutations in multiple symmetric lipomatosis

Area of Science:

• Neurology
• Genetics
• Metabolic Disorders

Background:

• Multiple symmetric lipomatosis (MSL) is a rare disorder characterized by excessive subcutaneous fat accumulation, primarily in the neck and trunk.
• Peripheral neuropathy is frequently observed in MSL patients, predominantly males.
• Previous studies suggest a potential link between MSL and mitochondrial abnormalities.

Purpose of the Study:

• To review clinical, electrophysiological, morphological, biochemical, and molecular genetic findings in 17 MSL patients.
• To investigate the extent of central nervous system (CNS) involvement in MSL.
• To explore the etiological association between MSL and mitochondrial dysfunction.

Main Methods:

• Clinical assessment and electrophysiological studies (nerve conduction studies, EMG) were performed on 17 MSL patients.
• Muscle biopsies were analyzed for morphological changes, including ragged red fibers.
• Molecular genetic analysis was conducted to identify mitochondrial DNA (mtDNA) alterations.

Main Results:

• Electrophysiological studies revealed signs of CNS involvement in a majority of MSL patients.
• Muscle biopsies showed ragged red fibers in 8 out of 12 patients, indicating mitochondrial myopathy.
• Molecular genetic analysis identified multiple mtDNA deletions in one patient and the MERRF mutation (8344) in another.

Conclusions:

• MSL is associated with significant central nervous system involvement beyond peripheral neuropathy.
• Mitochondrial dysfunction is a key etiological factor in MSL, supported by morphological and genetic findings.
• This review consolidates evidence linking MSL to specific mitochondrial genetic defects, emphasizing the need for further research.