Dana Knutzen

The ‘possabilities’ are endless for Joubert syndrome

Dana Knutzen, board member, Joubert Syndrome and Related Disorder Foundation

This week, the Joubert Syndrome and Related Disorder Foundation (JSRDF) hosts their biannual conference in Chicago, Illinois. The conference brings together the world’s experts on Joubert syndrome as well as families touched by this disorder. This year’s theme, the Possabilities Project, focuses on the skills that children and adults with the syndrome can develop and the milestones that they can reach. Sessions will increase knowledge about health-related issues of Joubert syndrome and how best to manage them.

Joubert syndrome is a genetic disorder characterized by a specific brain difference known as the molar tooth sign. Additional neurological impairments can result in low muscle tone, abnormal breathing patterns, eye movement differences, and developmental delay or intellectual disabilities of varying degrees. It is estimated that 1 in 100,000 individuals is born with Joubert syndrome each year.

As the largest nonprofit support organization for Joubert syndrome and related disorders, the JSRDF has been providing information about these rare conditions to families all over the world since 1992. The foundation is an international network of parents, family members, caregivers, healthcare providers, and researchers dedicated to supporting those affected by the condition. Although raising awareness for this rare disorder is key to its mission, the foundation also plays an active role in education, research, and medical management guidelines.

Joubert syndrome is often more than just neurological concerns—individuals may present with other clinical features at birth, such as severe visual impairments, extra fingers and toes (polydactyly), and protrusions of the brain and the membranes that are caused by an incompletely closed neural tube (occipital encephalocele). Additional clinical features may progress over time and can include kidney and liver disease. Given the clinical heterogeneity of the disorder, Joubert syndrome may often be misdiagnosed during the newborn and early childhood years. Alerting healthcare providers to the common features of the disorder can decrease the time to diagnosis, allowing for earlier interventions and therapies and the initiation of screening for potentially life-limiting complications, including kidney and liver disease.

Over the past ten years, there has been a rapid increase in recognition of the underlying genetic cause of Joubert syndrome. Several genes are currently associated with this disorder. Joubert syndrome is typically inherited in an autosomal recessive pattern, in which parents of a child with the syndrome would be presumed carriers and at 25 percent risk with each pregnancy to have another child with Joubert syndrome. Although advances in gene identification and genetic testing have solved the diagnostic odyssey for some families with Joubert syndrome, testing remains uninformative for many others, implying that additional genetic causes remain to be identified.

Understanding rare disorders such as Joubert syndrome can take decades. This is often due to the limited number of individuals affected with the syndrome, the scarcity of researchers, and the lack of financial support. Although tremendous progress has been made in defining the clinical spectrum and underlying genetic causes of Joubert syndrome, there is still much more to learn. Working together, we can increase our understanding and potentially develop treatments to improve the lives of those with Joubert syndrome.