The Col11a1 gene is disrupted in this naturally occurring mutation, chondrodysplasia (cho). Linkage studies map Col11a1 to the same region of Chr 3 as the cho mutation. There is a single nucleotide (C) deletion in the Col11a1 gene downstream of the translation initiation codon in mRNA from cho homozygotes; this disrupts the reading frame of the mRNA and introduces a premature stop codon. (J:22965)