Autonomic symptoms in carriers of the m.3243A>G mitochondrial DNA mutation.
BACKGROUND
The m.3243A>G mutation can cause multisystem medical problems and can affect the autonomic nervous system.


OBJECTIVE
To study the frequency and spectrum of autonomic symptoms associated with the m.3243A>G mitochondrial DNA point mutation. Design, Setting, and Patients We studied a cohort of 88 matrilineal relatives from 40 families, including 35 fully symptomatic patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS), 53 carrier relatives, and 16 controls using a questionnaire based on existing standard instruments for the evaluation of autonomic dysfunction. We compared the questionnaire with an expert evaluation. We compared data among the 3 groups using the Mantel-Haenszel chi(2) test to determine the statistical significance of differences between groups.


RESULTS
Mutation carriers frequently had symptoms of autonomic dysfunction, specifically gastrointestinal and orthostatic intolerance.


CONCLUSIONS
Carriers of the m.3243A>G mutation have frequent autonomic symptoms. The m.3243A>G mutation should be considered as an etiological factor in patients with autonomic dysfunction and a medical or family history suggestive of mitochondrial disease. Because some autonomic symptoms are treatable, early detection and proactive management may mitigate the burden of morbidity.
Parsons
Timothy
T
Department of Neurology, Columbia University, 710 W 168th St, New York, NY 10032, USA.
Weimer
Louis
L
Engelstad
Kristin
K
Linker
Alex
A
Battista
Vanessa
V
Wei
Ying
Y
Hirano
Michio
M
Dimauro
Salvatore
S
De Vivo
Darryl C
DC
Kaufmann
Petra
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000209:etiology / Q000235:genetics*; D016009:Chi-Square Distribution; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D006801:Humans; D017241:MELAS Syndrome / Q000150:complications; D008297:Male; D008875:Middle Aged; D028361:Mitochondrial Diseases / Q000150:complications; D009154:Mutation / Q000235:genetics*; D055815:Young Adult
D004272:DNA, Mitochondrial