Sahar Saleem

n/a

Joubert syndrome and related cerebellar disorders (JSRD) are a group of recessive congenital ataxia conditions usually showing neonatal hypotonia, dysregulated breathing rhythms, oculomotor apraxia, and mental retardation. The pathognomonic finding in JSRD is the unique molar tooth sign (MTS) on brain imaging. There is a tremendously broad spectrum of signs and symptoms mainly including kidney, retina, and liver disease, along with polydactyly and facial dysmorphisms. Here we propose a new diagnostic classification within JSRD that includes four major subtypes. To test this classification, we performed a systematic recruitment and genetic evaluation from a single referral center in Egypt. Thirteen families were identified, four showed evidence of linkage to one of the four known genetic loci, three showed novel AHI1 mutations, and nine were excluded from known loci. Each family could be classified into one of the four subtypes. This classification may thus be useful in the evaluation of patients with JSRD.

GLOSSARY: BUN = blood urinary nitrogen; COACH = cerebellar vermis hypo/aplasia-oligophrenia-ataxia-ocular coloboma-hepatic fibrosis; CORS = cerebello-oculo-renal syndrome; CVH = cerebellar vermis hypoplasia; DAS = Dekaban-Arima syndrome; DWM = Dandy-Walker malformation; JSRD = Joubert syndrome and related cerebellar disorders; LCA = Leber congenital amaurosis; lod = logarithm of odds score; MKS = Meckel-Gruber syndrome; MTS = molar tooth sign; NPH = nephronophthisis; NRC = National Research Center; OFD-VI = oro-facio-digital syndrome type VI; PCH = pontocerebellar hypoplasia; RHO = rhombencephalosynapsis; SLS = Senior-Loken syndrome.