AUTHOR=Liu Dongjing , Ban Hyo-Jeong , El Sergani Ahmed M. , Lee Myoung Keun , Hecht Jacqueline T. , Wehby George L. , Moreno Lina M. , Feingold Eleanor , Marazita Mary L. , Cha Seongwon , Szabo-Rogers Heather L. , Weinberg Seth M. , Shaffer John R. 

TITLE=PRICKLE1 × FOCAD Interaction Revealed by Genome-Wide vQTL Analysis of Human Facial Traits

JOURNAL=Frontiers in Genetics

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2021.674642

DOI=10.3389/fgene.2021.674642

ISSN=1664-8021

ABSTRACT=<p>The human face is a highly complex and variable structure resulting from the intricate coordination of numerous genetic and non-genetic factors. Hundreds of genomic loci impacting quantitative facial features have been identified. While these associations have been shown to influence morphology by altering the mean size and shape of facial measures, their effect on trait variance remains unclear. We conducted a genome-wide association analysis for the variance of 20 quantitative facial measurements in 2,447 European individuals and identified several suggestive variance quantitative trait loci (vQTLs). These vQTLs guided us to conduct an efficient search for gene-by-gene (G × G) interactions, which uncovered an interaction between <italic>PRICKLE1</italic> and <italic>FOCAD</italic> affecting cranial base width. We replicated this G × G interaction signal at the locus level in an additional 5,128 Korean individuals. We used the hypomorphic <italic>Prickle1</italic><sup><italic>Beetlejuice</italic></sup> (<italic>Prickle1</italic><sup><italic>Bj</italic></sup>) mouse line to directly test the function of Prickle1 on the cranial base and observed wider cranial bases in <italic>Prickle1<sup><italic>Bj/Bj</italic></sup>.</italic> Importantly, we observed that the Prickle1 and Focadhesin proteins co-localize in murine cranial base chondrocytes, and this co-localization is abnormal in the <italic>Prickle1</italic><sup><italic>Bj/Bj</italic></sup> mutants. Taken together, our findings uncovered a novel G × G interaction effect in humans with strong support from both epidemiological and molecular studies. These results highlight the potential of studying measures of phenotypic variability in gene mapping studies of facial morphology.</p>