Joubert syndrome is a disorder that affects many parts of the body. The signs and symptoms of this condition vary among affected individuals, even among members of the same family.
Joubert syndrome can be caused by mutations in more than 30 genes. The proteins produced from these genes are known or suspected to play roles in cell structures called primary cilia. Primary cilia are microscopic, finger-like projections that stick out from the surface of cells and are involved in sensing the physical environment and in chemical signaling. Primary cilia are important for the structure and function of many types of cells, including brain cells (neurons) and certain cells in the kidneys and liver. Primary cilia are also necessary for the perception of sensory input, which is interpreted by the brain for sight, hearing, and smell.
Joubert syndrome is estimated to affect between 1 in 80,000 and 1 in 100,000 newborns. However, this estimate may be too low because Joubert syndrome has such a large range of possible features and is likely underdiagnosed. Particular genetic mutations that cause this condition are more common in certain ethnic groups, such as Ashkenazi Jewish, French-Canadian, and Hutterite populations.
Joubert syndrome typically has an autosomal recessive pattern of inheritance, which means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they usually do not show signs and symptoms of the condition.
Published Date: July 01, 2017Published By: National Institutes of Health