Mutations in the COL2A1 gene interfere with the assembly of type II collagen molecules, resulting in a reduced amount of this type of collagen in the body. Instead of forming collagen molecules, the abnormal COL2A1 protein builds up in cartilage cells (chondrocytes). These changes disrupt the normal development of bones and other connective tissues, leading to the<unk>  abnormalities characteristic of<unk> . This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In some cases, an affected person inherits the mutation from one affected parent. Other cases may result from new mutations in the gene. These cases occur in people with no history of the disorder in their family.
Platyspondylic lethal skeletal dysplasia, Torrance type
Spondyloepimetaphyseal dysplasia, Pakistani type
Tricho–rhino–phalangeal syndrome type 2
Microphthalmia, syndromic 12 
Cerebral dysgenesis–neuropathy–ichthyosis–keratoderma syndrome
Microcephalic osteodysplastic primordial dwarfism type II
Spondyloepimetaphyseal dysplasia, Strudwick type
X-linked recessive chondrodysplasia punctata