COL2A1 and type 2 collagenopathy: In addition, type II collagenopathies can be divided into two main groups based on typical radiographic patterns: delayed ossification of the juxtatruncal bones, including pear-shaped vertebrae, in the group of «SED and similar phenotypes», and abnormal growth of tubular bones with their dumbbell-like expansion in the group of «KD/STL1» [8].