COL27A1 and Steel syndrome: To further explore the Steel syndrome founder allele for potential insights into skeletal biology, and the potential mechanism(s) by which defects in COL27A1 result in osteochondrodysplasia, we collected long bones (femurs and tibias) from heterozygous (Col27a1G682R/+) and homozygous (Col27a1G682R/G682R) KI mice, and WT littermates at P1 to perform histological analyses.