In genome wide association studies (GWAS). families based studies tend to have less power to detect genetic associations than population based studies. such as case-control studies. This can be an issue when testing if genes in a family based GWAS have a direct effect on the phenotype of interest or if the genes act indirectly through a secondary phenotype. https://www.kaliboat.com/product-category/beverage-equipmentunderbar-equipmentunderbar-glass-racks/