There are limitations to applying Mahalanobis distance matching methods. First, Mahalanobis distance is generally employed to identify multivariate outliers. Here, we have used it to find the closest group for each sample in multivariate space. However, it is possible the sample may still be an outlier from the closest group, especially if the individual is from a population not well represented on the reference panel. Indeed, the 1KGP reference panel is missing human populations including those from Oceania and the Middle East. An important scientific venture will be the inclusion and representation of all human populations, which will see the current method improved with respect to both resolution and applicability.
