Case Reports in Pediatrics

Case Report

Joubert Syndrome Presenting with Motor Delay and Oculomotor Apraxia

Table 1

Molecular genetics of Joubert’s syndrome (adapted from Parisi) [7].
Gene symbolLocus and inheritanceProtein nameLocalisationMTSLiverColRDRenalPolyOEOMAAssociations with other ciliopathies
JBTS1INPP5E9q34ArInositol polyphosphate-5-phosphatase EBB, PC++ − − + − − − +—
JBTS2TMEM21611q13ArTransmembrane protein 216BB, PC++ − +++++++MKS
JBTS3AHI16q23ArJouberin/Abelson helper integration site 1BB, PC++ − + / − +++ − − +NPHP
JBTS4NPHP12q13ArNephrocystin-1BB, PC+/− − − +++ − − +SLSN, NPHP
JBTS5CEP29012q21ArCentrosomal protein of 290 kDaBB, PC++++++++ − + + / − MKS, LCA, BBS, SLSN
JBTS6TMEM678q21ArTransmembrane protein 67/MeckelinBB, PC+++++ − + + / − + + / − COACH, MKS, NPHP, BBS (modifier)
JBTS7RPGRIP1L16q12ArRPGR-interacting protein 1-like proteinBB, PC+++ + / − + / − ++++ + / − COACH, MKS
JBTS8ARL13B3q11ArADP-ribosylation factor-like 13BBB, PC++ − − + − − + − —
JBTS9CC2D2A4p15ArCoiled-coil and C2 domains-containing protein 2ABB++++++ − + + / − COACH, MKS
JBTS10CXORF5Xp22XrChromosome X open reading frame 5PC+ − − + − + − − OFD1, SGBS2
JBTS11*TTC21B2q24AdTetratricopeptide repeat-domain 21BIFT, PC+???????ATD4, NPHP
JBTS12KIF715q26ArKinesin family member 7IFT+ − − − − + − − ACLS, HLS2
JBTS13TCTN112q24ArTectonic 1BB, PC+ − − − − − − − —
*The paper describing JBTS11 by Davis et al. [9] screened for TTC21B mutations in patients with classic Joubert’s syndrome but does not mention associated clinical features.
Ar: autosomal recessive; Ad: autosomal dominant; Xr: X-linked recessive; BB: basal body; PC: primary cilium; IFT: intraflagellar transport; MTS: molar tooth sign; Col: coloboma; RD: retinal dystrophy; Poly: polydactyly; OE: occipital encephalocele; OMA: oculomotor apraxia; SLSN: Senior-Løken syndrome; BBS: Bardet-Biedl syndrome; LCA: Leber’s congenital amaurosis; COACH: Coloboma, Oligophrenia/developmental delay, Ataxia, Cerebellar vermis hypoplasia, Hepatic fibrosis; MKS: Meckel syndrome; NPHP: Nephronophthisis; OFD1: oral-facial-digital syndrome 1, SGBS2: Simpson-Golabi-Behmel syndrome type 2; ATD4: Asphyxiating thoracic dystrophy type 4; ACLS: Acrocallosal syndrome; HLS2: Hydrolethalus syndrome 2.