(e.g. atrial fibrillation or coronary artery disease) but more recentlycompleted novel genes associated with stroke have been identified.

To date, all associations have been stroke subtype specifici.e. associated with specific types of stroke such as large artery stroke,cardioembolic stroke, or small vessel disease. This emphasises thatstroke describes a clinical syndrome rather than a specific disease anddifferent pathophysiological mechanisms underlie different strokesubtypes. It also emphasises the importance of careful stroke subtypingin any genetic studies.

The genes identified so far account for only a small variance of totalstroke risk. Therefore, they are not yet useful in predicting stroke risk.However, they are providing novel insights into strokewhichmay openup new treatments. For example, the recent association of variants inHDAC9 with large artery stroke is particularly interesting. HDACexpression has been shown to be increased in carotid plaques, anddrugs which inhibit HDAC such as sodium valproate appear to slowatherosclerosis in animal models.

doi:10.1016/j.clinbiochem.2013.05.019

Genetics of childhood obesityThe impact of nutritionGeorge DedoussisHarokopio University, Greece

Prevalence of overweight and obesity in adolescents has increasedover the last decades. Although the increased obesity levels have beenattributed to environmental changes, a strong genetic component hasalso been shown to contribute. Genome-wide association studies(GWAS) have been successful in identifying multiple genetic lociassociated with BMI and/or obesity. Large GWAS meta-analyses, fromthe Genetic Investigation of Anthropometric Traits (GIANT) (Spelioteset al., 2010) and Early GrowthGenetics (EGG) consortia (Bradfield et al.,2012), have identified multiple BMI-associated loci. The GIANT meta-analysis (Speliotes et al., 2010) of 249,796 individuals confirmed 14established obesity susceptibility loci and identified 18 new lociassociated with adult BMI. Twenty-three of the 32 variants also showeddirectionally consistent effects on children's BMI. The EGG meta-analysis replicated associations for seven established adult BMI variantsand identified two novel loci robustly associated with increasedchildhood obesity risk. We investigated the individual and cumulativeeffects of established adult BMI and childhood obesity associated lociwith BMI and overweight risk in a sample of Greek adolescents, theTEENAGE study. Our findings also support evidence for a large sharedgenetic component between adult and childhood BMI and obesity andvalidate the TEENAGE study as a cohort inwhich to study the genetics ofanthropometric traits. In addition we show gene-lifestyle interactionson obesity indices underlying the complexity of the disease.

doi:10.1016/j.clinbiochem.2013.05.020

Abstracts1150