Familial aggregation of Parkinson's disease may affect progression of motor symptoms and dementia

• Published in: Movement disorders Vol. 32; no. 2; pp. 241 - 245
• Main Authors: Gaare, Johannes Jernqvist, Skeie, Geir Olve, Tzoulis, Charalampos, Larsen, Jan Petter, Tysnes, Ole‐Bjørn
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.02.2017
• Subjects: Age of Onset; Aged; Dementia - epidemiology; Dementia - etiology; disease characteristics; Disease Progression; Endophenotypes; familial aggregation; family history; Female; first‐degree relatives; Follow-Up Studies; genetics; Humans; Male; Mental Status and Dementia Tests; Middle Aged; Movement disorders; Norway - epidemiology; Parkinson Disease - complications; Parkinson Disease - epidemiology; Parkinson's disease; Pedigree; prospective cohort; Severity of Illness Index; first-degree relatives; prospective cohort; Parkinson's disease; genetics; family history; familial aggregation; disease characteristics
• ISSN: 0885-3185; 1531-8257; 1531-8257
• DOI: 10.1002/mds.26856

ABSTRACT Background Familial aggregation has been described in PD of both early and late onset, but has not been studied in a true population‐based sample. Moreover, little is known about its association with disease progression and endophenotypes. Objectives The objectives of this work were to determine familial aggregation of idiopathic PD in a population‐based cohort and study the association with clinical endophenotypes and disease progression. Methods We examined family history data from the Norwegian ParkWest study, a well‐characterized, population‐based cohort of incident PD patients and age‐matched healthy controls. Family data were collected at baseline with a simplified questionnaire (192 cases and 193 controls) and after 3 years of longitudinal follow‐up using an extended questionnaire (172 cases and 171 controls). Results Compared to the controls, the PD patients had an increased relative risk of having a first‐degree relative with PD when using the extended questionnaire (relative risk = 1.988; P = 0.036), but not when using the simplified questionnaire (relative risk = 1.453; P = 0.224). There was no significant difference in age of onset or motor subtype (P = 0.801). However, cases with a family history of PD had reduced progression over 7 years as measured by UPDRS II (P = 0.008) and smaller rate of decrease of MMSE (P = 0.046). Conclusions Our findings confirm familial aggregation in a population‐based cohort of idiopathic PD. Moreover, we show that positive family history of PD in patients is associated with a slower progression of PD symptoms and cognitive decline. © 2016 International Parkinson and Movement Disorder Society