Unusual clinical findings and Complex III deficiency in a family with myotonic dystrophy.
Myotonic dystrophy type 1 (DM1), an autosomal dominant disease characterized by a CTG expansion in the 3' region of the DMPK gene in chromosome 19, is a highly heterogeneous disease. In this study, we present a family with early onset-classical type DM, and a homogeneous phenotype highlighted by severe neuromuscular symptoms and mental dysfunction with subcortical-type dementia. Neuroradiological abnormalities included brain atrophy, white matter lesions, and basal ganglia calcifications. A very large CTG triplet expansion was present in the DMPK locus in leukocytes in the three patients. One patient showed ragged-red fibers (RRF) and a defect complex III of the respiratory chain, but no mutations were found in the cytochrome b gene of mtDNA.
Seijo-Martínez
Manuel
M
Department of Neurology, Complexo Hospitalario de Pontevedra, Spain. mseijom@meditex.es
Castro del Río
María
M
Campos
Yolanda
Y
Palau
Francisco
F
Arenas
Joaquín
J
Teijeira
Susana
S
Fernández Hojas
Roberto
R
Navarro
Carmen
C
D017668:Age of Onset; D015139:Blotting, Southern; D001921:Brain / Q000473:pathology*; D002888:Chromosomes, Human, Pair 19; D039721:Diagnostic and Statistical Manual of Mental Disorders; D014450:Electron Transport Complex III / Q000172:deficiency / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000453:epidemiology / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology*; D065636:Myotonin-Protein Kinase; D010375:Pedigree; D010641:Phenotype; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D019680:Trinucleotide Repeat Expansion
C585517:DMPK protein, human; D065636:Myotonin-Protein Kinase; D017346:Protein Serine-Threonine Kinases; D014450:Electron Transport Complex III