Novel polymerase gamma (POLG1) gene mutation in the linker domain associated with parkinsonism

Rachel Dolhun,Erin M Presant,Peter Hedera

doi:10.1186/1471-2377-13-92

Abstract

BackgroundMutations in the POLG1 gene have variable phenotypic presentations and a high degree of clinical suspicion is necessary for their recognition. Parkinsonism and ataxia are the most common movement disorders associated with POLG1 mutations but no phenotype-genotype correlation has been established.Case presentationWe identified a male patient with progressive external ophthalmoplegia who also developed a progressive bradykinesia, rigidity and camptocormia in the third decade. Parkinsonism was partially responsive to dopaminegic replacement. His father and brother had reportedly similar clinical problems. Genetic analysis identified a novel mutation p.K512M in the POLG1 gene.ConclusionThis report further expands the spectrum of POLG1-associated neurologic problems with the report of a novel mutation in the linker region of the gene, which are rarely associated with parkinsonism.

Highlights

Mutations in the POLG1 gene have variable phenotypic presentations and a high degree of clinical suspicion is necessary for their recognition
Greater than one hundred pathogenic mutations in this enzyme have been found since it was first described [2]. These include, but are not limited to parkinsonism, chronic progressive external ophthalmoplegia (CPEO), cerebellar ataxia, sensory polyneuropathy, Alpers-Huttenlocher syndrome, which is characterized by progressive encephalopathy with seizures and hepatic failure, isolated myoclonic epilepsy or non-syndromic liver failure. [2,3,4,5,6] This wide variety of distinct and seemingly unrelated clinical problems with both autosomal dominant (AD) or recessive (AR)
The presented patient reflects a significant phenotypic variability associated with mutations in the POLG1 gene

Summary

Conclusion

This report further expands the spectrum of POLG1-associated neurologic problems with the report of a novel mutation in the linker region of the gene, which are rarely associated with parkinsonism.

Background

Findings

Conclusions