Early Onset Parkinson's disease due to DJ1 mutations: An Indian study

Abstract

Introduction: Early Onset Parkinson's Disease (EOPD) is genetically heterogeneous. PARK2 mutations are the commonest cause of autosomal recessive EOPD followed by PINK1.DJ1 mutations is rare and there is scarce literature on its phenotype and long term outcome.

Objectives: We undertook a retrospective study to determine the prevalence of DJ1 mutation(s) in an Indian population and describe the clinical features and long term outcome of EOPD patients with these mutations.

Methods: One hundred EOPD patients and 114 controls were evaluated. All the seven coding exons of DJ1 gene were screened for novel and reported mutations by PCR- Sanger sequencing.

Results: A novel homozygous missense mutation (c.313 A > T, p. Ile105Phe) in exon 5 was seen in one patient and four unrelated patients had a homozygous missense single nucleotide variant rs71653619 (c.293 G > A, p.Arg98Gln). The clinical phenotype comprised of asymmetrical onset, slowly progressive Parkinsonism with levodopa induced motor restlessness in a patient with the novel mutation (c.313 A > T, p. Ile105Phe) while subjects with c.293 G > A, p.Arg98Gln had early onset levodopa responsive symmetrical Parkinsonism.

Conclusion: DJ1 mutations account for ∼5% of EOPD patients from the Indian population. This study further adds to the clinical spectrum of EOPD with DJ1 mutations.

Keywords: DJ1mutation; Early onset Parkinson's disease; Genetics; Phenomenology.