In definition, Joubert syndrome is a rare autosomal recessive disorder which is caused by the lack of the cerebellar vermis. The actual cause of Joubert syndrome is unknown, but parents who have a child affected with the syndrome have a one in four chance of having another affected child.
Since this is a recessive trait, both parents could be carriers of the disorder, and not be affected. The growth of the cerebellar vermis takes place between the sixth and twelfth weeks of pregnancies, so it is believed that this is when the Joubert syndrome first begins to develop.
In a human, the cerebellum is the second largest part of the brain, which controls movement, and receives signals from the eyes and ears. Noticeable at birth, the lack of the cerebellar vermis caused by the Joubert syndrome can cause unbalanced breathing, with points of heavy breathing, to points where the patient looses their breath. The eye can also be affected, usually with quick and abrupt movements of the pupil.
Problems that arise in the central nervous system as a result of Joubert syndrome can cause muscle weakness and developmental delays in infants, and affect the person’s balance and coordination. Learning impairments, inability to run or climb stairs, and extra fingers and toes are all common symptoms of the Joubert syndrome.
Currently, genetic testing is unable to detect Joubert syndrome, but prenatal ultrasound tests may be possible to detect it. Treatments cannot get rid of the disorder, but can help the quality of life for someone affected by it. Infants with unusual breathing may require a respiratory monitor.
Physical therapy, speech therapy, and auditory training are all possible ways to help minimize the effects of the syndrome. Infants with unusual breathing may lead to sudden death or a coma, but can live longer, still requiring medical care. Some individuals have died in the first four years, and some have lived into their thirties.
