This study reported the therapeutic effects of VPA, LEV, CZP, and TPM as monotherapies and LEV in combination with CZP in 17 patients diagnosed with
MERRF syndrome.
Merrf syndrome is a neurodegenerative disorder that worsens over time and often results in an early death.
Bresolin et al., "Rapid detection of the A--G(8344) mutation of mtDNA in Italian families with myoclonus epilepsy and ragged-red fibers (
MERRF)," American Journal of Human Genetics, vol.
Li et al., "Functional recovery of human cells harbouring the mitochondrial DNA mutation
MERRF A8344G via peptide-mediated mitochondrial delivery," Neurosignals, vol.
[5] Nonstandard abbreviations: LGMD, limb girdle muscular dystrophy; SCA, spinocerebellar ataxia; MELAS, mitochondrial encephalopathy, lactic acidosis and stroke-like episodes;
MERRF, myoclonic epilepsy with ragged-red fibers; NARP, neurogenic muscle weakness, ataxia and retinitis pigmentosa syndrome; CMT, Charcot-Marie-Tooth.
It is therefore not surprising that rare disorders stemming from mutations in the mitochondrial genome, such as
MERRF, MELAS, and the Kearn-Sayre syndrome, predominantly compromise the CNS, heart, and skeletal muscle.
HL appears to be associated with other mitochondrial disorders affecting organs that require high energy, such as myoclonic epilepsy with ragged-red fibers (
MERRF) or mt encephalomyopathy, lactic-acidosis, and stroke-like episodes (MELAS) disorders.
We read with interest the case report by Ban et al .[1] about a 17-year-old male with myoclonic epilepsy with ragged red fibers (
MERRF) syndrome being attributed to the mitochondrial tRNA glutamic acid( tRNA [Glu] )variant mitochondrial 14709T>C.
Simultaneous A8344G heteroplasmy and mitochondrial DNA copy number quantification in myoclonus epilepsy and ragged-red fibers (
MERRF) syndrome by a multiplex molecular beacon based real-time fluorescence PCR.
This disease category includes some relatively well-known disorders, including the mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes syndrome (MELAS) (21,22) and the myoclonic epilepsy with ragged-red fiber syndrome (
MERRF).
Among all the biopsy cases, we diagnosed more than 120 mitochondrial myopathy/encephalomyopathy cases, but only one of them is myoclonic epilepsy with ragged red fibers (
MERRF) harboring a novel mutation.