Is Langer mesomelic dysplasia inherited ?
Langer mesomelic dysplasia has a pseudoautosomal recessive pattern of inheritance. The SHOX gene is located on both the X and Y chromosomes (sex chromosomes) in an area known as the pseudoautosomal region. Although many genes are unique to either the X or Y chromosome, genes in the pseudoautosomal region are present on both sex chromosomes. As a result, both females (who have two X chromosomes) and males (who have one X and one Y chromosome) normally have two functional copies of the SHOX gene in each cell. The inheritance pattern of Langer mesomelic dysplasia is described as recessive because both copies of the SHOX gene in each cell must be missing or altered to cause the disorder. In females, the condition results when the gene is missing or altered on both copies of the X chromosome; in males, it results when the gene is missing or altered on the X chromosome and the Y chromosome.  A related skeletal disorder called Lri-Weill dyschondrosteosis occurs when one copy of the SHOX gene is mutated in each cell. This disorder has signs and symptoms that are similar to, but typically less severe than, those of Langer mesomelic dysplasia.