Joubert syndrome type 6

Joubert syndrome type 6

An autosomal recessive disorder (OMIM:610688) characterised by cerebellar ataxia, oculomotor apraxia, hypotonia, neonatal breathing abnormalities, 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
Caused by defects of TMEM67, which encodes meckelin, a key ciliary protein.