Joubert syndrome: A review

Abstract

We review 72 previously reported and 29 new patients with the possible diagnosis of Joubert syndrome. We define diagnostic criteria for this syndrome and present the data available in 94 patients that fulfill our criteria. We present the data regarding the clinical, neuroradiological, and ophthalmological manifestations and the prognosis of these 94 patients. We propose a classification of the patients with this diagnosis in 2 groups: those with retinal dystrophy and those without. Retinal dystrophy runs true in families and was never absent when renal cysts were reported.

Abnormal cerebellar development and axonal decussation due to mutations in AHI1 in Joubert syndrome

“…Individuals with Joubert syndrome have motor and behavioral abnormalities, including an inability to walk due to severe clumsiness and 'mirror' movements, and cognitive and behavioral disturbances [5][6][7][8][10][11][12] . Here we identified a locus associated with Joubert syndrome, JBTS3, on chromosome 6q23.2-q23.…”

“…Affected individuals show weakness, abnormal breathing and eye movements, clumsiness, cognitive difficulties and autistic behaviors [5][6][7][10][11][12][13] . Joubert syndrome is defined by the absence of the cerebellar vermis (Fig.…”

“…1e,f) and by the 'molar tooth sign' , formed by an abnormal configuration of the superior cerebellar peduncles (SCPs) that connect the cerebellum to the midbrain and thalamus (Fig. 1d) [1][2][3][5][6][7][9][10][11][12] . Joubert syndrome is defined by the absence of the cerebellar vermis (compare normal MRI, Fig.…”

“…1c with Fig. 1f) [1][2][3][5][6][7][9][10][11][12] . Corticospinal fibers that normally decussate in the medulla also fail to cross the midline in Joubert syndrome [1][2][3]9 , causing mirror movements, in which both hands move synchronously instead of alternating, in affected individuals.…”

Missense variants in TMEM67 in a patient with Joubert syndrome

“…Joubert syndrome (JS) is an autosomal recessive disorder characterized by a cerebellar and brainstem malformation called the “molar tooth sign,” hypotonia with eventual ataxia and developmental delays 1. The molar tooth sign involves hypoplasia of the cerebellar vermis, thick superior cerebellar peduncles, and a particularly deep interpeduncular fossa and is mandatory in the diagnosis of Joubert syndrome 2…”