Advances in molecular neuroscience can help render focused, reliable diagnoses for some mtDNA disorders in which specific causative mutations are known, such as LHON, MELAS, MERRF
, and KearnsSayre syndrome.
net 1,2,3,4,5,6,7; regional conferences MERRF
SYNDROME See: Myoclonus; Mitochondrial Disorders METABOLIC DISORDERS See also: Acidemia, Organic; Galactosemia; Lactic Acidosis; Maple Syrup Urine Disease; Niemann-Pick Disease; Phenylketonuria (PKU) Association for Neurometabolic Disorders 5223 Brookfield Ln.
, MELAS, Kearns-Sayre), Krebs acid cycle defects, gluconeogenesis defects (e.
b) MELAS, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes; homo, homoplasmy; hetero, heteroplasmy; LHON, leber hereditary optic neuropathy; MERRF
, myoclonic epilepsy and ragged red fibers; NARP, neuropathy, ataxia, and retinitis pigmentosa; mult.
To rule out the most common point mutations in mtDNA, several point mutations causing MEZAS, MERRF, NARP, Leigh, and (or) LHON syndromes may need to be evaluated.
mtDNA mutations that account for adult forms of myopathy, cardiomyopathy, MERRF, multisystem disorders, and mutations associated with aging such as Alzheimer and Parkinson diseases are apparently underrepresented.
The A3243G mutation accounts for 80% of patients with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) , and the A8344G mutation accounts for 80% of patients with MERRF
(myoclonic epilepsy and ragged-red fibers) [3, 4].