Childhood brain tumours: associations with parental occupational exposure to solvents.

BACKGROUND: Parental occupational exposures have been associated with childhood brain tumours (CBT), but results are inconsistent. Few studies have studied CBT risk and parental solvent exposure, suggesting a possible association. We examined the association between CBT and parental occupational exposure to solvents in a case-control study. METHODS: Parents of 306 cases and 950 controls completed detailed occupational histories. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for both maternal and paternal exposure to benzene, other aromatics, aliphatics and chlorinated solvents in key time periods relative to the birth of their child. Adjustments were made for matching variables (child's age, sex and state of residence), best parental education and occupational exposure to diesel exhaust. RESULTS: An increased risk of CBT was observed with maternal occupational exposures to chlorinated solvents (OR=8.59, 95% CI 0.94-78.9) any time before birth. Paternal exposure to solvents in the year before conception was associated with an increased CBT risk: OR=1.55 (95% CI 0.99-2.43). This increased risk appeared to be mainly attributable to exposure to aromatic solvents: OR=2.72 (95% CI 0.94-7.86) for benzene and OR=1.76 (95% CI 1.10-2.82) for other aromatics. CONCLUSIONS: Our results indicate that parental occupational exposures to solvents may be related to an increased risk of CBT.

KIBRA genetic polymorphism influences episodic memory in later life, but does not increase the risk of mild cognitive impairment.

A common T-->C polymorphism of the KIBRA gene has been recently associated with worse performance on tests of episodic memory. This should aimed to determine whether older adults with the KIBRA CC genotype (1) have worse episodic memory than T-allele carriers and, (2) are more likely to express the phenotype of amnestic mild cognitive impairment (MCI). Our Cross-sectional investigation of 312 adults aged 50-89 years free of dementia included genotyping of the KIBRA rs17070145 gene and the assessment of episodic memory to Establish a Registry for Alzheimer's Disease (CERAD). Participants were considered to have MCI if their memory scores were 1.5 standard deviations below the mean norm for the population. 138/312 participants carried the KIBRA CC genotype. Their immediate and delayed recall scores were significantly lower than the scores of carriers of the T allele (P < 0.05; adjusted for age, gender and pre-morbid IQ), although the effect size of the CC genotype was weak (0.2). Amongst our volunteers, 133 had MCI, of whom 63 (47.4%) had the CC genotype. There was no association between KIBRA genotype and MCI phenotype (TT/CT versus CC; adjusted odds ratio = 1.70, 95%CI = 0.74, 3.90). We concluded that the KIBRA T-->C polymorphism contributes to modulate episodic memory amongst community-dwelling older adults free of dementia, but plays no obvious role in the phenotypic expression of MCI. Future studies should aim to clarify the long term implications of this polymorphism on cognitive function and to identify other genes involved in the modulation of memory that might confer greater risk of MCI in later life.