Radiologic Features of Type II and Type XI Collagenopathies

Abstract

Type II collagen is a major component of the cartilage matrix. Pathogenic variants (ie, disease-causing aberrations) in the type II collagen gene (COL2A1) lead to an abnormal structure of type II collagen, causing a large group of skeletal dysplasias termed type II collagenopathies. Because type II collagen is also located in the vitreous body of the eyes and inner ears, type II collagenopathies are commonly associated with vitreoretinal degeneration and hearing impairment. Type II collagenopathies can be radiologically divided into two major groups: the spondyloepiphyseal dysplasia congenita (SEDC) group and the Kniest-Stickler group. The SEDC group is characterized by delayed ossification of the juxtatruncal bones, including pear-shaped vertebrae. These collagenopathies comprise achondrogenesis type 2, hypochondrogenesis, SEDC, and other uncommon subtypes. The Kniest-Stickler group is characterized by disordered tubular bone growth that leads to "dumbbell" deformities. It comprises Kniest dysplasia and Stickler dysplasia type 1, whose radiographic manifestations overlap with those of type XI collagenopathies (a group of disorders due to abnormal type XI collagen) such as Stickler dysplasia types 2 and 3. This phenotypic overlap is caused by type II and type XI collagen molecules sharing part of the same connective tissues. The authors describe the diagnostic pathways to type II and type XI collagenopathies and the associated differential diagnoses. In addition, they review the clinical features and genetic bases of these conditions, which radiologists should know to participate in multidisciplinary care and translational research.

A primer on skeletal dysplasias

“…Spondyloepiphyseal dysplasia congenita (SEDC) is the most common short-trunked bone dysplasia with predominant involvement of the spine and the epiphyses [ 10 , 11 ]. SEDC is the common condition among type II collagenopathies—a group of disorders caused by abnormal type II collagen [ 12 ]. A clinical feature includes short stature varying in severity, predominantly caused by a short trunk and short neck.…”

Deciphering the active constituents of Dabushen decoction of ameliorating osteoarthritis via PPARγ preservation by targeting DNMT1

“…PPARγ plays a role in the regulation of matrix decomposition ( Afif et al, 2007 ). Previous reports showed that collagen II is a major component of the cartilage matrix ( Handa et al, 2021 ). MMP-13 can hydrolyze collagen II, which is considered as a significant biomarker to assess OA therapeutic effects and OA progression ( Corciulo et al, 2017 ).…”

Histological features of articular cartilage and bone marrow reparative potential under conditions of coxarthritis in patients with radiographic signs of epiphyseal dysplasia

“…One of the consequences of genetically determined anomalies of type II collagen synthesis, which include numerous congenital anomalies of the development of epiphyses under the general term «epiphyseal dysplasias» (ED) [1][2][3][4], is the development of early osteoarthritis, accompanied by a corresponding decrease in the quality of life and an increase in the need in medical and social assistance [2,[5][6][7][8][9][10]. According to published information [1,3,4,[10][11][12], 5-29 % of the population have phenotypic signs of various types of collagenopathies with clinically expressed lesions of the musculoskeletal system, and osteoarthritis is steadily progressing on their basis. There is currently no etiological therapy for this impairment, which reduces the treatment of patients to slowing down the progression of osteoarthritis through symptomatic therapy with the timely application of radical treatment methods in order to preserve the social adaptation of patients [5,6,9,10,[13][14][15].…”