Predominant dystonia with marked cerebellar atrophy: a rare phenotype in familial dystonia.
BACKGROUND
Dystonia syndromes constitute a heterogeneous group of phenotypes that may be caused by different heredodegenerative, metabolic, or genetic diseases.


OBJECTIVE
To describe the characteristics of an unusual dystonia-plus phenotype associated with cerebellar atrophy.


METHODS
We selected patients with predominant dystonia and cerebellar atrophy among the 861 families referred to us for genetic testing from 1992 to 2003. The main secondary heredodegenerative causes and the major genes responsible for hereditary dystonias and autosomal dominant or recessive ataxias were excluded.


RESULTS
We identified 12 patients in 8 families with an unusual dystonia-plus phenotype characterized by dystonia and cerebellar atrophy on brain MRI. The mean age at onset was 27.3 +/- 11.5 years (range: 9 to 42 years) and the mean disease duration 14.7 +/- 7.7 years (range: 4 to 30). At onset, dystonia was focal or multifocal, mainly affecting vocal cords (n = 8) and upper limbs (n = 2). During the disease course spasmodic dysphonia became severe in five patients, leading to complete aphonia in two. Dystonia became generalized in five. Cerebellar ataxia was limited to unsteadiness in most patients and progressed very slowly. The paucity of clinical cerebellar signs contrasted with the marked cerebellar atrophy on brain MRI in most patients. Four families with two affected sibs support the hypothesis of an autosomal recessive disorder. However, X-linked inheritance is possible since only men were affected.


CONCLUSIONS
We have characterized an unusual familial phenotype associating dystonia and cerebellar atrophy in 12 male patients.
Le Ber
I
I
INSERM U679, Département de Génétique, Cytogénétique et Embryologie, France.
Clot
F
F
Vercueil
L
L
Camuzat
A
A
Viémont
M
M
Benamar
N
N
De Liège
P
P
Ouvrard-Hernandez
A M
AM
Pollak
P
P
Stevanin
G
G
Brice
A
A
Dürr
A
A
D000328:Adult; D001284:Atrophy / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D002524:Cerebellar Ataxia / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D002526:Cerebellar Diseases / Q000235:genetics / Q000473:pathology* / Q000503:physiopathology*; D002531:Cerebellum / Q000473:pathology* / Q000503:physiopathology*; D025063:Chromosome Disorders / Q000235:genetics; D004252:DNA Mutational Analysis; D018450:Disease Progression; D020821:Dystonic Disorders / Q000235:genetics / Q000473:pathology* / Q000503:physiopathology*; D005808:Genes, Recessive / Q000235:genetics; D040181:Genetic Diseases, X-Linked / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005820:Genetic Testing; D005838:Genotype; D006801:Humans; D040582:Inheritance Patterns / Q000235:genetics; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D010641:Phenotype