Joubert Syndrome Genetics & Prevalence
Joubert syndrome is an autosomal recessive disorder, which means that both parents are carriers of the disorder. Most people carry different faulty genes but in a recessive disorder parents, though healthy themselves, carry the same faulty genes, and risk passing them on to their children.
Future pregnancies for parents of a child with Joubert Syndrome carries a 1 in 4 chance (25%) of a child being affected or a 3 in 4 chance (75%) of a child being unaffected.
Prenatal testing for Joubert Syndrome may be detected on a fetal ultrasound performed at 18 to 20 weeks of pregnancy. If a specific gene has been identified in an affected child in the family, then this gene can be tested for in a blood sample.
National Organisation for Rare Disorders estimates that the prevalence of Joubert syndrome is 1/258,000 but is probably an underestimate of the true prevalence, which may be closer to 1/100,000.