title: Monozygotic twins concordant for narcolepsy-cataplexy without any detectable abnormality in the hypocretin (orexin) pathway.
abstract: Narcolepsy with cataplexy is thought to be a hypocretin ligand or hypocretin receptor deficiency syndrome caused by genetic and environmental factors. We looked for an abnormality of the hypocretin pathway in HLA-DQB1*0602-positive monozygotic twins who were concordant for narcolepsy-cataplexy. They had normal cerebrospinal fluid concentrations of hypocretin-1, and we found no mutation in the prepro-hypocretin gene or either hypocretin receptor gene. Our finding points to the existence of presumably genetic forms of narcolepsy with cataplexy without any demonstrable defect in the hypocretin pathway.
authors.affiliation: Neurology Department, University Hospital, CH 8091, Zurich, Switzerland.
authors.forename: Ramin
authors.initials: R
authors.lastname: Khatami
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Maret
authors.forename: Esther
authors.initials: E
authors.lastname: Werth
authors.forename: Julia
authors.initials: J
authors.lastname: Rétey
authors.forename: Dagmar
authors.initials: D
authors.lastname: Schmid
authors.forename: Friedrich
authors.initials: F
authors.lastname: Maly
authors.forename: Mehdi
authors.initials: M
authors.lastname: Tafti
authors.forename: Claudio L
authors.initials: CL
authors.lastname: Bassetti
mesh_terms: D000328:Adult; D002352:Carrier Proteins / Q000134:cerebrospinal fluid*; D004200:Diseases in Twins; D005260:Female; D006683:HLA-DQ Antigens / Q000032:analysis; D059866:HLA-DQ beta-Chains; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins / Q000032:analysis; D009290:Narcolepsy / Q000134:cerebrospinal fluid / Q000175:diagnosis / Q000235:genetics* / Q000276:immunology; D009479:Neuropeptides / Q000134:cerebrospinal fluid* / Q000172:deficiency; D000068797:Orexins; D017286:Polysomnography; D014430:Twins, Monozygotic
chemical_list: D002352:Carrier Proteins; C000596229:HCRT protein, human; D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D009479:Neuropeptides; D000068797:Orexins