* ncas: For binary traits, name of the column storing the number of cases by variants (optional)
* ncont: For binary traits, name of the column storing the number of controls by variants (optional)
* beta_or_Z: name of the column storing the genetic effect (beta) in the gwas file. This column will be used only to retrieve the sign of the genetic effect with respect to the reference and effect allele.
* se: standard error
* OR : For binary traits, Odd ratio when available. Not to be confounded with the genetic effect size or 'beta'.
* index-type: precise the type of index
* imputation_quality: (Optional) column containing individual-based imputation quality. Will be used to filter low quality imputation data from GWASs if the option --imputation-quality-treshold is used
