Clinical Study of Symptoms and Various Anomalies of Patients with Joubert Syndrome

ABSTRACT

PURPOSE: Joubert syndrome is known to be an autosomal recessive disorder characterized by cerebellar vermian dysgenesis with many symptoms and variety of other malformations. We studied the relevant symptoms and various malformations of seven patients diagnosed as Joubert syndrome at our institution. METHODS: Seven children with cerebellar vermian dysgenesis consistent with Joubert syndrome were included in our study. Each child was diagnosed at the Seoul National University Children's Hospital from Feb. 1991 to Feb. 1995. We studied the frequency of each symptom of Joubert syndrome and the associated malformations of the selected cases. RESULTS: All seven patients had no family members affected. Also their parental consanguinity were not found. Sex ratio was 1.3 1 (4 males and 3 females) showing no significant sex difference. Ages at diagnosis were less than one year old. Six patients in our study had developmental delay, which was the most frequent symptom. Four patients had ataxia; four patients had hypotonia; three patients had abnormal ocular movements such as nystagmus or saccadic palsy; only one patient had episodic tachypnea in neonatal period; and in one case there were tongue protrusion and seizure, respectively. In two cases there were occipital meningoceles, agenesis of corpus callosum, and cleft palates, respectively. In one case there were cystic renal disorder, neuronal heterotopia, absence of septum pellucidum, and polydactyly, respectively. None had retinal dystrophy or chorioretinal coloboma. CONCLUSIONS: The cardinal symptoms of Joubert syndrome are unexplainable episodic tachypnea alternating with apnea during neonatal period, abnormal ocular movement such as nystagmus or saccadic palsy, ataxia, hypotonia, and developmental delay. The presence of such symptoms should alert the clinician to apply appropriate test such as neuroradiologic study including brain MRI etc. Some of the inconstantly associated features of Joubert syndrome include congenital retinal dystrophy, chorioretinal coloboma, and cystic kidney disease. The patients should be examined routinely with electroretinogram, fundoscopy, and kidney ultrasonogram for early detection or exclusion of the associated anomalies. We stress the importance of genetic counselling for the families of Joubert syndrome as well as that of the prompt supportive therapy for the patient.