What are the genetic changes related to Meckel syndrome ?
Meckel syndrome can be caused by mutations in one of at least eight genes. The proteins produced from these genes are known or suspected to play roles in cell structures called cilia. Cilia are microscopic, finger-like projections that stick out from the surface of cells and are involved in signaling pathways that transmit information between cells. Cilia are important for the structure and function of many types of cells, including brain cells and certain cells in the kidneys and liver.  Mutations in the genes associated with Meckel syndrome lead to problems with the structure and function of cilia. Defects in these cell structures probably disrupt important chemical signaling pathways during early development. Although researchers believe that defective cilia are responsible for most of the features of this disorder, it remains unclear how they lead to specific developmental abnormalities of the brain, kidneys, and other parts of the body.  Mutations in the eight genes known to be associated with Meckel syndrome account for about 75 percent of all cases of the condition. In the remaining cases, the genetic cause is unknown. Mutations in several other genes have been identified in people with features similar to those of Meckel syndrome, although it is unclear whether these individuals actually have Meckel syndrome or a related disorder (often described as a "Meckel-like phenotype").