Fig. 1

Example of the distributions of the Ct values in R21X carriers and non-carriers. a Exemplary ast-PCR amplification plot. b Discrimination of the two Ct distributions using a statistical clustering approach. The orange and pink horizontal bars below the x-axis identify the samples that cannot be uniquely assigned to one of the two distributions and are therefore excluded from the analysis. Orange bar: upper 1% of the carrier distribution and lower 1% of the non-carrier distribution. Pink bar: upper 2.5% of the carrier distribution and lower 2.5% of the non-carrier distribution (more conservative; used in this analysis). Plot generated using the provided R script