Maria et al proposed criteria for Joubert syndrome. The authors are from the University of Florida in Gainesville and Children's University Hospital in Zurich.


Inheritance: autosomal recessive


Genetic locus: unknown


Pathology in posterior fossa:

(1) hypoplasia or dysplasia of vermis

(2) elongation of the caudal midbrain tegmentum

(3) dysplasia of the caudal medulla


Neurologic features:

(1) hypotonia in all patients, especially during neonatal period and infancy

(2) developmental delay in several domains (motor, language, adaptive behaviors, general development)

(3) motor delay involves head control, rolling over, sitting, standing and walking

(4) unable to perform the transition from kneeling to standing without assistance

(5) unable to walk, or else delayed walking with unstable gait and extreme calcaneal eversion while standing

(6) typically socially well integrated, pleasant and easily guided


Neuroimaging findings:

(1) "molar tooth sign" on MRI in the axial plane, which consists of:

(1a) deeper-than-normal posterior interpeduncular fossa

(1b) prominent or thickened superior cerebellar peduncles

(1c) vermian hypoplasia or dysplasia

(2) rostrally displaced and abnormally shaped 4th ventricle (MRI in sagittal plane)

(3) clefting of the vermis (MRI in coronal and axial planes)


Facial features:

(1) high, rounded eyebrows

(2) broad nasal bridge

(3) mild epicanthus

(4) anteverted nostrils

(5) a triangular-shaped, open mouth

(6) irregular tongue protrusion

(7) low-set, coarse ears


Ocular findings:

(1) retinal dysplasia (rarely resulting in blindness)

(2) colobomas

(3) nystagmus

(4) strabismus

(5) ptosis

(6) apraxia

(7) vestibulo-ocular cancellation and pursuit defects


Visceral findings:

(1) episodic hyperpnea and/or apnea, more pronounced in neonatal period and during infancy

(2) progressive, microcystic renal disease


Rare findings:

(1) macro or microcephaly

(2) occipital meningocele

(3) epilepsy

(4) ocular fibrosis

(5) soft tissue tumors of the tongue

(6) congenital heart defects

(7) pectus excavatum

(8) vocal cord paralysis

(9) esophageal reflux

(10) duodenal atresia

(11) choanal atresia

(12) Hirschsprung's disease

(13) hepatic abnormalities

(14) polydactyly


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