Fig. 1: Histogram depicting allele frequency (AF) distribution for all filtered variants across 109 Moroccan samples.
From: Moroccan genome project: genomic insight into a North African population

The histogram shows the count of variants per 5% AF interval. The most prominent peak corresponds to variants with rare alternate AFs below 5%, whereas rare or unobserved reference variants have 100% alternate AFs, indicating the less common variants.