Gene Variant Associated with Novel Inherited Dystonia
Mutation within the gene PRKRA associated with autosomal recessive, dystonia parkinsonism syndrome
MONDAY, Feb. 4 (HealthDay News) -- A single gene mutation is associated with a novel inherited form of dystonia, a movement disorder, adding to 15 other genes already associated with various forms of dystonia, according to research published online Feb. 4 in The Lancet Neurology.
Sarah Camargos, M.D., from the National Institutes of Health in Bethesda, Md., and colleagues performed genomewide single nucleotide polymorphism genotyping of two unrelated Brazilian families with young-onset generalized dystonia parkinsonism. The inheritance pattern was consistent with autosomal recessive inheritance. Similar analyses were performed on several control populations.
The researchers found that the disease was associated with 277 homozygous markers covering a 1.2 Mb locus, designated DYT16, on chromosome 2q31.2. Sequencing all the exons of the 11 predicted transcripts revealed a single mutation (P222L) in the stress-response gene PRKRA encoding the protein kinase interferon-inducible double-stranded RNA-dependent activator.
"We describe a mutation within the gene PRKRA that segregates with a novel, autosomal recessive, dystonia parkinsonism syndrome," Camargos and colleagues conclude. "These patients have progressive, generalized, early-onset dystonia with axial muscle involvement, oromandibular (sardonic smile), laryngeal dystonia and, in some cases, parkinsonian features, and do not respond to levodopa therapy."