Cooperative Genome-Wide Analysis Shows Increased Homozygosity in Early Onset Parkinson's Disease

Parkinson's disease (PD) occurs in both familial and sporadic forms, and both monogenic and complex genetic factors have been identified. Early onset PD (EOPD) is particularly associated with autosomal recessive (AR) mutations, and three genes, PARK2, PARK7 and PINK1, have been found to carry mutations leading to AR disease. Since mutations in these genes account for less than 10% of EOPD patients, we hypothesized that further recessive genetic factors are involved in this disorder, which may appear in extended runs of homozygosity

Cyclized NDGA modifies dynamic α-synuclein monomers preventing aggregation and toxicity.

Growing evidence implicates α-synuclein aggregation as a key driver of neurodegeneration in Parkinson's disease (PD) and other neurodegenerative disorders. Herein, the molecular and structural mechanisms of inhibiting α-synuclein aggregation by novel analogs of nordihydroguaiaretic acid (NDGA), a phenolic dibenzenediol lignan, were explored using an array of biochemical and biophysical methodologies. NDGA analogs induced modest, progressive compaction of monomeric α-synuclein, preventing aggregation into amyloid-like fibrils. This conformational remodeling preserved the dynamic adoption of α-helical conformations, which are essential for physiological membrane interactions. Oxidation-dependent NDGA cyclization was required for the interaction with monomeric α-synuclein. NDGA analog-pretreated α-synuclein did not aggregate even without NDGA-analogs in the aggregation mixture. Strikingly, NDGA-pretreated α-synuclein suppressed aggregation of naïve untreated aggregation-competent monomeric α-synuclein. Further, cyclized NDGA reduced α-synuclein-driven neurodegeneration in Caenorhabditis elegans. The cyclized NDGA analogs may serve as a platform for the development of small molecules that stabilize aggregation-resistant α-synuclein monomers without interfering with functional conformations yielding potential therapies for PD and related disorders

Diagnostic pitfalls in Parkinson's disease: case report Dificuldades diagnósticas na doença de Parkinson: relato de caso

Parkinson's disease (PD) is characterized by resting tremor, rigidity and bradykinesia. In 80% of cases, the disorder begins with upper limb resting tremor. However, there are some presenting atypical features that make the diagnosis even more difficult and intriguing. The disorder can have its onset below 40 years old, characterizing early-onset parkinsonism, which differential diagnosis possibilities are varied. Atypical presentations include a pure akinetic-rigid syndrome, the initial manifestations occurring in the lower limbs, and pain as the most important or sole manifestation. These atypical features are unusual, but can be seen in clinical practice. We present a 37 years old woman with early-onset parkinsonism beginning with an akinetic-rigid syndrome in the lower limbs whose first symptom was left leg pain, which diagnosis was made after 4 years of onset and after 16 referrals to several experts in different fields. We discuss these atypical features and the diagnostic pitfalls in PD.<br>A doença de Parkinson (DP) caracteriza-se pela tríade de tremor, rigidez e bradicinesia. Em cerca de 80% dos casos inicia-se com tremor em membros superiores. Entretanto, certas atipias na apresentação desta entidade tornam seu diagnóstico ainda mais desafiador. A doença pode iniciar-se abaixo dos 40 anos de idade, caracterizando o parkinsonismo de início precoce. Apresentações atípicas incluem uma síndrome rígido-acinética pura, as manifestações inaugurais ocorrendo em membros inferiores, e uma síndrome dolorosa podendo ser um sintoma inicial proeminente ou o único sintoma. Estas atipias, apesar de infreqüentes, são encontradas na prática clínica diária. Discutimos estas características atípicas ao apresentarmos uma paciente de 37 anos com quadro rígido-acinético de instalação precoce, iniciado em membros inferiores, cujo sintoma predominante era dor, cujo diagnóstico somente foi feito após 4 anos do início e após 16 avaliações médicas por vários especialistas. Discutiremos as dificuldades diagnósticas que os médicos podem encontrar quando da avaliação de pacientes com DP