| This gene encodes the alpha-1 chain of type II collagen, a fibrillar collagen found in cartilage and the vitreous humor of the eye. Mutations in this gene are associated with achondrogenesis, chondrodysplasia, early onset familial osteoarthritis, SED congenita, Langer-Saldino achondrogenesis, Kniest dysplasia, Stickler syndrome type I, and spondyloepimetaphyseal dysplasia Strudwick type. In addition, defects in processing chondrocalcin, a calcium binding protein that is the C-propeptide of this collagen molecule, are also associated with chondrodysplasia. There are two transcripts identified for this gene. [provided by RefSeq, Jul 2008],disease:Defects in COL2A1 are a cause of primary avascular necrosis of femoral head (ANFH) [MIM:608805], also called ischemic necrosis of the femoral head or osteonecrosis of the femoral head. ANFH causes disability that often requires surgical intervention. Most cases are sporadic, but families in which there is an autosomal dominant inheritance of the disease have been identified. It has been estimated that 300,000 to 600,000 people in the United States have ANFH. Approximately 15,000 new cases of this common and disabling disorder are reported annually. The age at the onset is earlier than that for osteoarthritis. The diagnosis is typically made when patients are between the ages of 30 and 60 years. The clinical manifestations, such as pain on exertion, a limping gait, and a discrepancy in leg length, cause considerable disability. Moreover, nearly 10 percent of the 500,000 total-hip arthroplasties performed each year in the United States involve patients with ANFH. As a result, this disease creates a substantial socioeconomic cost as well as a burden for patients and their families.,disease:Defects in COL2A1 are a cause of rhegmatogenous retinal detachment autosomal dominant (DRRD) [MIM:609508]. Rhegmatogenous retinal detachment most frequently results from a break or tear in the retina that allows fluid from the vitreous humor to enter the potential space beneath the retina. It is often associated with pathologic myopia and in most cases leads to visual impairment or blindness if untreated.,disease:Defects in COL2A1 are the cause of a variety of chondrodysplasia including hypochondrogenesis and osteoarthritis.,disease:Defects in COL2A1 are the cause of achondrogenesis hypochondrogenesis type 2 (ACG2) [MIM:200610]. ACG2 is a disease characterized by the absence of ossification in the vertebral column, sacrum and pubic bones.,disease:Defects in COL2A1 are the cause of Kniest syndrome (KS) [MIM:156550], also known as Kniest dysplasia or metatropic dwarfism type II. KS is a moderately severe chondrodysplasia phenotype that results from mutations in the COL2A1 gene. Characteristics of the disorder include a short trunk and extremities, mid-face hypoplasia, cleft palate, myopia, retinal detachment, and hearing loss.,disease:Defects in COL2A1 are the cause of Legg-Calve-Perthes disease (LCPD) [MIM:150600], also known as Legg-Perthes disease or Perthes disease. LCPD is characterized by loss of circulation to the femoral head, resulting in avascular necrosis in a growing child. Clinical pictures of the disease vary, depending on the phase of disease progression through ischemia, revascularization, fracture and collapse, and repair and remodeling of the bone.,disease:Defects in COL2A1 are the cause of multiple epiphyseal dysplasia with myopia and conductive deafness (EDMMD) [MIM:132450]. Multiple epiphyseal dysplasia is a generalized skeletal dysplasia associated with significant morbidity. Joint pain, joint deformity, waddling gait, and short stature are the main clinical signs and symptoms. EDMMD is an autosomal dominant disorder characterized by epiphyseal dysplasia associated with progressive myopia, retinal thinning, crenated cataracts, conductive deafness.,disease:Defects in COL2A1 are the cause of osteoarthritis with mild chondrodysplasia [MIM:604864]. Osteoarthritis is a common disease that |
