Links
[1] http://ghr.nlm.nih.gov/search?query=C21orf2
[2] https://disorders.eyes.arizona.edu/references/axial-spondylometaphyseal-dysplasia-caused-c21orf2-mutations
[3] https://disorders.eyes.arizona.edu/references/axial-spondylometaphyseal-dysplasia-confirmation-and-further-delineation-new-smd-retinal
[4] https://disorders.eyes.arizona.edu/references/axial-spondylometaphysealdysplasia