Height-reducing variants and selection for short stature in Sardinia

We report sequencing-based whole-genome association analyses to evaluate the impact of rare and founder variants on stature in 6,307 individuals on the island of Sardinia. We identified two variants with large effects. One is a stop codon in the GHR gene, relatively frequent in Sardinia (0.87% vs <0.01% elsewhere), which in homozygosity causes the short stature Laron syndrome. We find that it reduces height in heterozygotes by an average of 4.2 cm (−0.64 s.d). The other variant, in the imprinted KCNQ1 gene (MAF = 7.7% vs <1% elsewhere) reduces height by an average of 1.83 cm (−0.31 s.d.) when maternally inherited. Additionally, polygenic scores indicate that known height-decreasing alleles are at systematically higher frequency in Sardinians than would be expected by genetic drift. The findings are consistent with selection toward shorter stature in Sardinia and a suggestive human example of the proposed “island effect” reducing the size of large mammals.