CTTNBP2 and idiopathic osteonecrosis of the femoral head: Although no obvious connection was found between this gene and CHD in the original study [6], some more recent phenotype associations have been listed in the GWAS catalogue (https://www.ebi.ac.uk/gwas/home) for CTTNBP2 that are worth noting: juvenile idiopathic arthritis and idiopathic osteonecrosis of the femoral head.