332 JEB 332 DEJ JEB 1980s 1985 – 1986 A polyclonal antibody to amnion identifies a so far unknown component of the DEJ which may be involved in JEB Polyclonal antibody AA3 (serum 6/2) 1986 A monoclonal antibody GB3 also reacts with a new protein of the DEJ which seems to be abnormally expressed in JEB 1986 GB3 might be a tool for the diagnosis of JEB JEB Normal skin 1988 GB3 reacts with BM 600 (nicein), a large sized glycoprotein of the DEJ, made of 3 subunits 1990 GB3 is a useful (the best?) tool for rapid diagnosis of lethal JED 1992 - 1993 BM 600 / nicein = kalinin = laminin 5 1992 - 1995 Identification of the genes and the first mutations of LAMA3, LAMB3, LAMC2 1992 - 1995 Individualisation of JEB-PA and identification of the first mutations of ITGB4 Molecular diagnosis of JEB 1992-2014 149 patients having JEB Clinical data obtained from clinicians taking care of the patients Immunodiagnosis Molecular diagnosis on blood genomic DNA Parental inheritance when possible Origin of patients 2 90 16 17 6 4 3 1 4 1 4 1 7 3 59 42 2 11 3 4 Repartition of JEB cases (149) 16% COLXVII 15% 100 67% LAMA3 25 17% LAMB3 2% 9% LAMB3 LAMC2 ITGB4 15% LAMA3 43% 24 16% ITA6 ITB4 COLXVII JEB due to laminin-332 3 genes/subunits: LAMA3/α3, LAMB3/β3, LAMC2/γ2 100 patients 77 JEB generalized severe (JEB-Herlitz) 196 mutations (1 mutation only in 4 patients) 82 distinct mutations (33 novel) 5 diagnoses on fetus after therapeutic interruption of pregnancy for suspicion of JEB-H 462insT 565-2A>G* Q115X 628delG 643delA 234delCA* E210K Q243X* G245D C290X Q96X 183+2T>C R42X LN 823-1G>A 910 delC 1034ins77* (957ins77) Q373X* 1132+5G>A * novel reported homozygous MUTATIONS N terminal alpha3 29insC* beta3 LE LE LE LE LE LE LE LE 252delT 300delG* gamma2 S19X* LE LE LE LE LE L4 R95X* R245X 764-10T>G 953G>T 1037delT R337X Y355X* R896X 2869+1G>A Q961X 3070-1G>A R586X* 1587delAG Y575X 1760delC* R635X* 2012delT R660X Y722X* 2292-delC 2378delT R851X* 2702-12delG 2910-1G>A R972X 3228+1G>T 3304delG 3457delC Q1083X* 1782delGC* E281X* K462X LG5 LG1 2380del6* C terminal LE LE 4783-5T>G* 4782+1G>A LG4 LG2 3416delA LG3 4300insA* Y1230X* 462insT 565-2A>G* Q115X 628delG 643delA Q96X 183+2T>C R42X LN 29insC* LE LE LE LE LE LE E210K Q243X* G245D C290X 823-1G>A 910 delC 1034ins77* (957ins77) Q373X* 1132+5G>A Collagen VII binding site * Laminin-6 interaction site novel recurrent Homozygous 1587delAG Y575X 1760delC* R635X* 2012delT R660X Y722X* 2292-delC 2378delT R851X* 2702-12delG 2910-1G>A R972X 3228+1G>T 3304delG 3457delC Q1083X* Laminin-332 beta 3 chain - 65 patients. 53 JEB-H - 44 % of JEB cases - 65 % of lam-332 cases - 45 distinct mutations - 20 new mutations LE Laminin-332 alpha 3 chain LE 252delT 300delG* S19X* - 22 patients, 12 JEB-H - 15 % of JEB cases Cleavage site E281X* - 22 % of lam-332 cases K462X Syndecan binding site - 20 distinct mutations - 13 new mutations Heparan binding * novel recurrent Homozygous Integrins binding site 2380del6* LG5 LG4 LG1 LG2 3416delA LG3 4783-5T>G* 4782+1G>A 4300insA* Y1230X* Cleavage site Cleavage site Laminin-332 gamma2 chain - 13 patients, 12 JEB-H - 9 % of JEB cases - 13 % of lam-332 cases - 17 distinct mutations - 3 new mutations * novel recurrent Homozygous Nidogen - fibulin binding LE LE LE LE LE R586X* L4 LE LE R95X* R245X 1782delGC 764-10T>G * 953G>T 1037delT R337X Y355X* R896X 2869+1G>A Q961X 3070-1G>A JEB due to integrin α6β4 2 genes/subunits: ITGA6/α6, and ITGB4/β4 25 patients JEB-PA 17 % of JEB cases 18 lethal JEB-PA 48 mutations (1 mutation only in 2 patients) 31 distinct mutations (12 novel) ITGA6: 3 mutations ITGB4: 28 mutations MUTATIONS ITGA6-B4 alpha6 beta4 4851delCA 3977-19T>A 3807delC 3793+1G>A 3793+2insT 3656-1G>A COLXVII, plectin, BP230 binding site R1450X W1240X cytoplasmic * novel reported homozygous C terminal 286C>T* 2149insC Cell membrane lam-332 binding site Fibronectin III like domain Transmembranous domain Cystin rich domain 1770+4A>C 1379-2A>G C562W N318I R283C R252C* 1141delG 665delG 600insC 576-2A>G E115X 310delC 264G>A 103delC C61Y* N terminal extracellular R540X* JEB due to collagen XVII 24 patients 16 % of JEB cases 40 mutations identified 32 distinct mutations (18 novel) 161delT* 485-1G>A 1246+2T>C G446S 1344delGT C458X N terminal cytoplasmic Cell membrane NC16A A6 chain binding site extracellular Collagenic domain 3077delT 3280delG 3303C>T 3393del8 E1156X R1226X 3932insC B4 chain binding site col15 1587ins3* R566X 1850-2A>C G606D R625X* 2167delC R795X 2441-2A>G 2441-1G>T MUTATIONS COLXVII - 24 patients - 16 % of JEB cases - 32 distinct mutations Lam-332 binding site Q1403X * C terminal novel Homozygous Molecular diagnosis of JEB Large series of genotyped JEB Identification of 66 novel mutations Phenotype–genotype correlations under evaluation Geographical repartition of some recurrent mutations of great help when screening a candidate gene for a new patient Helpful for clinicians, patients and families Accurate diagnosis and prognosis Genetic counseling and PND Ex vivo gene therapy for JEB Cellules souches Biopsie cutanée Greffe Epithelium Transduction (vecteur viral) Ex vivo gene therapy for JEB Proof of concept Ker β3-/- control pLXSN β3 Wt Normal hemidesmosomes α3 IV γ2 β3 α3 VI IV γ2 Laminin 332 + β3 Gagnoux-Palacios et al. Lab Invest, 1997 Vailly et al. Gene Ther, 1998, Gagnoux-Palacios et al. J Biol Chem ,1996, Dellambra et al. Hum Gene Ther, 1998 Ex vivo gene therapy for JEB Proof of concept LEFT UPPER LEG RIGHT UPPER LEG 6 months 1 year Mavilio F. Nat Med. 2006 Ex vivo gene therapy for JEB Recruitement of patients Localized JEB Regulatory requirements or logistical difficulties SIN lentivirus vectors (Genethon) Unit for cell and gene therapy should be upgraded for gene transfer Collaboration is needed for epidermal stem cell culture under GPC conditions Jean Paul Ortonne Guerino Meneguzzi Alexandra Charlesworth Anne Spadafora Patrick Verrando Joelle Vailly, and others… C. LAGUENY Nurse coordinator C. CHIAVERINI Dermatologist JP. LACOUR Coordinator A. CHARLESWORTH Research ingeneer S. SERRE Secretary
© Copyright 2024 ExpyDoc
