Joubert syndrome type 2

Joubert syndrome type 2

An autosomal recessive disorder (OMIM:608091) characterised by ataxia, oculomotor apraxia, hypotonia, neonatal breathing defects, psychomotor delay, retinal dystrophy and renal disease.
Imaging
Cerebellar vermis hypoplasia/aplasia, thickened and reoriented superior cerebellar peduncles and abnormally large interpeduncular fossa, giving the appearance of a molar tooth on transaxial slices (molar tooth sign).
 
Molecular pathology
Defects of TMEM216, which encodes a transmembrane domain-containing protein required for tissue-specific ciliogenesis, cause Joubert syndrome type 2.