Genetics of psychic ability - A pilot case-control exome sequencing study.

Introduction: It is commonly believed that psychic ability, like many mental and physical traits, runs in families. This suggests the presence of a genetic component. If such a component were found, it would constitute a biological marker of psychic ability and inform environmental or pharmacologic means of enhancing or suppressing this ability.

Methods: A case-control study design was used to evaluate differences between psychic cases and non-psychic controls. Over 3,000 candidates globally were screened through two online surveys to locate people who claimed they and other family members were psychic. Measures of relevance to the claimed abilities (e.g., absorption, empathy, schizotypy) were collected and based on those responses, individuals with indications of psychotic or delusional tendencies were excluded from further consideration. Eligible candidates were then interviewed and completed additional screening tests. Thirteen individuals were selected as the final "psychic cases," and ten age-, sex-, and ethnicity-matched individuals with no claims of psychic ability were selected as controls. DNA from the saliva of these 23 participants was subjected to whole-exome sequencing. Two independent bioinformatics analyses were blindly applied to the sequenced data, one focusing exclusively on protein-coding sequences and another that also included some adjacent noncoding sequences.

Results: Sequencing data were obtained for all samples, except for one in the control group that did not pass the quality controls and was not included in further analyses. After unblinding the datasets, none of the protein-coding sequences (i.e., exons) showed any variation that discriminated between cases and controls. However, a difference was observed in the intron (i.e., non-protein-coding region) adjacent to an exon in the TNRC18 gene (Trinucleotide Repeat-Containing Gene 18 Protein) on chromosome 7. This variation, an alteration of GG to GA, was found in 7 of 9 controls and was absent from all psychic cases.

Discussion: The most conservative interpretation of these results is that they result from random population sampling. However, when the results are considered in relation to other lines of evidence, the results are more provocative. Further research is justified to replicate and extend these findings.