Furthermore, prior pre-clinical and clinical studies have implicated 14 of the 17 mapped genes, including three with potential bidirectional effects, in behavioural or neurological traits, including alcohol dependence (OSBPL5) [39], cocaine use (SLCO5A1) [40], anxiety (CCDC92) [41], depression (GNAI1) [42], encephalomyopathy and brain stress response (SLC25A42) [43, 44], and dementia/Alzheimer’s disease pathology (SIAH3, SRM, TP53I13) [45–47]. This evidence concerns the gene TP53I13 and mitochondrial DNA depletion syndrome, encephalomyopathic form with methylmalonic aciduria.