What are the genetic changes related to X-linked chondrodysplasia punctata 2 ?
X-linked chondrodysplasia punctata 2 is caused by mutations in the EBP gene. This gene provides instructions for making an enzyme called 3-hydroxysteroid-8,7-isomerase, which is responsible for one of the final steps in the production of cholesterol. Cholesterol is a waxy, fat-like substance that is produced in the body and obtained from foods that come from animals (particularly egg yolks, meat, poultry, fish, and dairy products). Although too much cholesterol is a risk factor for heart disease, this molecule is necessary for normal embryonic development and has important functions both before and after birth. It is a structural component of cell membranes and plays a role in the production of certain hormones and digestive acids.  Mutations in the EBP gene reduce the activity of 3-hydroxysteroid-8,7-isomerase, preventing cells from producing enough cholesterol. A shortage of this enzyme also allows potentially toxic byproducts of cholesterol production to build up in the body. The combination of low cholesterol levels and an accumulation of other substances likely disrupts the growth and development of many body systems. It is not known, however, how this disturbance in cholesterol production leads to the specific features of X-linked chondrodysplasia punctata 2.