HSPG2 and chondrodysplasia: Others and we have previously reported that the homozygous deletion of HSPG2 (HSPG2−/−) in mice results in lethal chondrodysplasia and in cardiovascular abnormalities, such as transposition of the great arteries (Arikawa‐Hirasawa et al. 1999; Costell et al. 1999, 2002).