Affiliations 

  • 1 Department of Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia. Electronic address: norlinah@gmail.com
  • 2 Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan; College of Medicine, National Taiwan University, Taipei, Taiwan; Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Biomedical Engineering, National Taiwan University, Taipei, Taiwan. Electronic address: chlin@ntu.edu.tw
Parkinsonism Relat Disord, 2024 Dec;129:107100.
PMID: 39183141 DOI: 10.1016/j.parkreldis.2024.107100

Abstract

Early Onset Parkinsonism (EOP) refers to parkinsonism occurring before the age of 50 years. The causes are diverse and include secondary and genetic causes. Secondary causes related to medications, inflammatory and infective disorders are mostly treatable and well recognized as they usually present with a relatively more rapid clinical course compared to idiopathic Parkinson's disease. Genetic causes of EOP are more challenging to diagnose especially as more of the non-PARK genes are recognized to present with typical and atypical parkinsonism. Some of the genetic disorders such as Spinocerebellar ataxia 2 (SCA2) and Spinocerebellar ataxia 3 (SCA3) may present with levodopa-responsive parkinsonism, indistinguishable from idiopathic Parkinson's disease. Additionally, some of the genetic disorders, including Wilson's disease and cerebrotendinous xanthomatosis (CTX), are potentially treatable and should not be missed. Due to the advent of next generating sequencing techniques, genetic analyses facilitate early identification and proper treatment of diverse causes of EOP. In this review, we outline the clinical approach of EOP highlighting the key clinical features of some of the non-PARK genetic causes of EOP and related investigations, which could assist in clinical diagnosis. This review also encompass genetic diagnostic approaches, emphasizing the significance of pretest counseling and the principles of bioinformatics analysis strategies.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.