ABSTRACT
BACKGROUND: Mutations in parkin are a known genetic risk factor for early onset Parkinson's disease (EOPD) but their role in non-motor manifestations is not well established. Genetic factors for depression are similarly not well characterized. We investigate the role of parkin mutations in depression among those with EOPD and their relatives. METHODS: We collected psychiatric information using the Patient Health Questionnaire and Beck Depression Inventory II on 328 genotyped individuals including 88 probands with early onset PD (41 with parkin mutations, 47 without) and 240 first and second-degree relatives without PD. RESULTS: Genotype was not associated with depression risk among probands. Among unaffected relatives of EOPD cases, only compound heterozygotes (n = 4), and not heterozygotes, had significantly increased risk of depressed mood (OR = 14.1; 95% CI 1.2-163.4), moderate to severe depression (OR = 17.8; 95% CI 1.0-332.0), depression (score ≥ 15) on the Beck Depression Inventory II (BDI-II) (OR = 51.9; 95% CI 4.1-657.4), and BDI-II total depression score (ß = 8.4; 95% CI 2.4-11.3) compared to those without parkin mutations. CONCLUSIONS: Relatives of EOPD cases with compound heterozygous mutations and without diagnosed PD may have a higher risk of depression compared to relatives without parkin mutations. These findings support evidence of a genetic contribution to depression and may extend the phenotypic spectrum of parkin mutations to include non-motor manifestations that precede the development of PD.
Subject(s)
Depression/genetics , Genetic Predisposition to Disease/genetics , Parkinson Disease/genetics , Parkinson Disease/psychology , Ubiquitin-Protein Ligases/genetics , Adult , Age of Onset , DNA Mutational Analysis , Female , Genotype , Heterozygote , Humans , Male , Middle Aged , Multiplex Polymerase Chain Reaction , Mutation , Neuropsychological Tests , Phenotype , Risk FactorsABSTRACT
In brief: Thirty-three prepubescent, pubescent, and postpubescent males participated in a nine-week resistive exercise program to test the hypothesis that pubescent males respond better to strength training than older and younger groups do. Before and after the program, the subjects' strength in elbow and knee flexion and extension was tested bilaterally on a dynamometer at two velocities. The posttest showed that all of the subjects gained strength in elbow flexion and extension and knee extension but not in knee flexion. The prepubescent group showed significantly greater gains than the others on three of the 16 tests, but in no case did the pubescent group show significantly greater gains.
