title: Mitochondrial recessive ataxia syndrome mimicking dominant spinocerebellar ataxia.
abstract: We studied the genetic background of a family with SCA, showing dominant inheritance and anticipation. Muscle histology, POLG1 gene sequence, neuropathology and mitochondrial DNA analyses in a mother and a son showed typical findings for a mitochondrial disorder, and both were shown to be homozygous for a recessive POLG1 mutation, underlying mitochondrial recessive ataxia syndrome, MIRAS. The healthy father was a heterozygous carrier for the same mutation. Recessively inherited MIRAS mutations should be tested in dominantly inherited SCAs cases of unknown cause, as the high carrier frequency of MIRAS may result in two independent introductions of the mutant allele in the family and thereby mimic dominant inheritance.
authors.affiliation: Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland. eino.palin@helsinki.fi
authors.forename: Eino J H
authors.initials: EJ
authors.lastname: Palin
authors.forename: Anna H
authors.initials: AH
authors.lastname: Hakonen
authors.forename: Mari
authors.initials: M
authors.lastname: Korpela
authors.forename: Anders
authors.initials: A
authors.lastname: Paetau
authors.forename: Anu
authors.initials: A
authors.lastname: Suomalainen
mesh_terms: D000328:Adult; D000074002:DNA Polymerase gamma; D004259:DNA-Directed DNA Polymerase / Q000235:genetics; D003937:Diagnosis, Differential; D005260:Female; D005799:Genes, Dominant; D006801:Humans; D008297:Male; D008875:Middle Aged; D028361:Mitochondrial Diseases / Q000175:diagnosis* / Q000235:genetics; D020754:Spinocerebellar Ataxias / Q000175:diagnosis* / Q000235:genetics
chemical_list: D000074002:DNA Polymerase gamma; D004259:DNA-Directed DNA Polymerase; C413027:POLG protein, human