The syndrome of mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes presenting without stroke.
OBJECTIVE
To study and describe a large family with the tRNA Leu(UUR) point mutation at position 3243 in mitochondrial DNA, which is associated with the syndrome of mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes.


METHODS
Survey; case series.


METHODS
University hospital inpatient and outpatient neurology department.


METHODS
Twelve patients from three generations in a family carrying the tRNA Leu(UUR) point mutation at position 3243 were studied.


METHODS
Clinical evaluation, muscle biopsy, and mitochondrial DNA point mutation quantitation of the syndrome of mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes in muscle and blood.


METHODS
Correlation between clinical, pathologic, and genotypic features.


RESULTS
Family members had various combinations of sensorineural hearing loss, retinal pigmentary degeneration, migraine, hypothalamic hypogonadism, and mild myopathy. Only one member had a strokelike episode at the age of 46 years. This patient had the highest point mutation percentage.


CONCLUSIONS
This report suggests that this point mutation may not be associated with stroke in all families and that whether patients develop stroke may depend on the percentage of mutant mitochondrial DNA and its tissue distribution.
Mosewich
R K
RK
Department of Neurology, Royal University Hospital, University of Saskatchewan, Saskatoon, Canada.
Donat
J R
JR
DiMauro
S
S
Ciafaloni
E
E
Shanske
S
S
Erasmus
M
M
George
D
D
D000328:Adult; D000368:Aged; D002561:Cerebrovascular Disorders / Q000150:complications* / Q000235:genetics; D004272:DNA, Mitochondrial / Q000032:analysis; D005260:Female; D005838:Genotype; D006319:Hearing Loss, Sensorineural / Q000150:complications; D006801:Humans; D007006:Hypogonadism / Q000150:complications; D007027:Hypothalamic Diseases / Q000150:complications; D007625:Kearns-Sayre Syndrome / Q000150:complications; D017241:MELAS Syndrome / Q000150:complications* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009135:Muscular Diseases / Q000150:complications; D009154:Mutation; D010375:Pedigree; D010857:Pigment Epithelium of Eye / Q000473:pathology
D004272:DNA, Mitochondrial