Classification+of+OI


 * How is it classified? **

The Classification of OI is currently up for debate as there are similar phenotypic (Clinical and Radiological) characteristics among the different types ofOI when genetically, there are different mutations which are causing the disorder. Below is a comparison of the 5 types of OI between phenotypic and genotypic characteristics which I compiled from a variety of sources 1,2,3,4,5,6.
 * **Types** || **Genetic Features** || **Clinical Features** || **Radiological Features** ||
 * **I** || **Autosomal Dominant:** COLIA 1; COLIA 2 || Mild severity; Sclerae Predominately Blue; Bone Deformity is rare; Normal height; Hearing loss in 60% cases; May have Dental phenotypes || **Skull****:** Wormian Bones **Ribs****:** No Fractures **Vertebrae:** Normal at Birth **Extremities****:** Normal at Birth **Other****:** Usually no congenital fractures or osteopenia ||
 * **II-A** || **Autosomal Dominant:** COLIA 1; COLIA 2 || Perinatal lethal; Congenital Fractures Present; Very Severe Bone Deformity; Dark Blue Sclerae; Short in Height; Respiratory Complications || **Skull:** Severly Diminished mineralization, wormian bones **Ribs:** Short, Broadened ribs and continuous fractures **Vertebrae:** Platyspondyly at birth **Extremities:** Thick, Short, crumpled shafts of long bones **Other:** Generalized osteopenia, multiple fractures and callous formation ||
 * **II-B** || **Autosomal Dominant:** COLIA 1; COLIA 2 **Autosomal Recessive:** CRTAP; LEPRE1: PPIB || Severe; Congenital Fractures; Severe Bone Deformity; Sclerae Dark Blue; Severely short Height; Hypermobility in Joints; Respiratory Complications || **Skull:** Diminished mineralization, wormian bones **Ribs:** thin ribs with discontinuous fractures **Vertebrae:** Platyspondyly at birth **Extremities:** Short, deformed long tubular bones **Other:** generalized osteopenia, multiple fractures with callus formation ||
 * **III** || **Autosomal Dominant:** COLIA 1; COLIA 2 **Autosomal Recessive:** CRTAP; LEPRE1; PPIB; SERPINF1 || Most severe type in young children; Usually Congenital Fractures; Moderate to Severe bone deformity; Blue/grey/white Sclerae; Hypermobity in Joints; Very Short Height; Hearing loss is common; Dentinogenesis Imperfecta (DI); Respiratory complications; Neurological complications || **Skull:** Diminished mineralization, wormian bones **Ribs:** Thin ribs with discontinuous fractures **Vertebrae:** Platyspondyly at birth **Extremities:** Short, deformed long tubular bones **Other:** general osteopenia, multiple fractures with callus formation ||
 * **IV** || **Autosomal Dominant:** COLIA 1; COLIA 2 **Autosomal Recessive:** PPIB || Moderate severity; Rarely Congenital Fractures; Mild-Moderate Bone Deformity; Normal-grey Sclerae; Varying Joint Hypermobility; Variable Height; Hearing Loss in about 42%; Varying DI || **Skull:** Diminished mineralization, sometimes with wormian bones **Ribs:** no congenital fractures **Vertebrae:** normal at birth **Extremities:** bowing of long bones **Other:** Generalized osteopenia ||
 * **V** || **Autosomal Dominant:** CRTAP || Moderately severity; Moderate Bone Deformity; Normal Sclerae; Varying Height; Varying Joint Hypermobility || **Skull:** Possibly diminished mineralization, sometimes with wormian bones **Ribs:** no congenital fractures **Vertebrae:** normal at birth **Extremities:** calcification of osseous membrane in forearms, bowing of long bones **Other:** generalized osteopenia ||
 * **VI** || **Autosomal Recessive:** Unidentified || Moderate severity and extremely rare; Moderate Bone Deformity; Normal Sclerae; Mild Short Height; Varying Joint Hypermobility || **Skull:** about 75% with no wormian bones **Ribs:** no congenital fractures **Vertebrae:** normal at birth **Extremities:** Bowing of long bones **Other:** Generalized osteopenia ||
 * **VII** || **Autosomal Recessive:** CRTAP || Some cases may appear as OI type IV and other cases appear as OI type II with white sclerae, small heads and round faces. Often short stature with short leg bones (humerus and femur) || See cases of OI Types II and IV ||
 * **VIII** || **Autosomal Recessive:** LEPRE1 || Cases are similar to OI Types II or III except for white sclerae. Severe growth deficiency and extreme under-mineralization of skeleton. || See cases of OI Types II and III ||

**>>> The Genes Involved >>>**


 * What is Osteogenesis Imperfecta? ||= Classification ||= The Genes Involved ||= Diagnosis and Treatment ||= References ||

Research by: Stacey St.Hilaire University of New Hampshire at Manchester Genomics and Bioinformatics