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Research Update SRSA Family Meeting Alan K. Percy, MD August 3 , 2013. Why rare diseases are important. True burden difficult to estimate Little general information available Absence of reliable or consistent data Difficult research funding Inadequate health service coverage
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Research UpdateSRSA Family Meeting Alan K. Percy, MDAugust 3, 2013
Why rare diseases are important • True burden difficult to estimate • Little general information available • Absence of reliable or consistent data • Difficult research funding • Inadequate health service coverage • Limited effective treatment • Biochemical and molecular facilities scarce
Natural History Study Goals • Advance clinical research • Develop longitudinal data through uniform protocols for data collection • Assess phenotype-genotype correlation • Engage in pilot projects to set stage for randomized clinical trials • Engage patients and advocates as partners • Enhance training of new investigators
The Past • Natural History Study I • Grant written in 2003 • Consisted of Angelman, Rett, and Prader-Willi Syndromes • Rett syndrome focus: Classic and Variant forms; MECP2 Duplication Disorder unknown • Enrollment began in March 2006 • Significant assistance from IRSA
Natural History Study • Goal: Enroll 1000 girls or women with RS • Must meet criteria or have MECP2 mutation • Purpose: expand phenotype-genotype studies and set stage for clinical trials • Principal sites: Baylor, Greenwood Genetic Center, and UAB • Travel Clinics: Oakland, Chicago, NJ, Florida • DMCC: Contact Registry • rarediseasesnetwork.epi.usf.edu
The Present • Natural History Study II • Continuation grant funded in 2009 • Rett syndrome now included Classic and Variant forms, MECP2 Duplication Disorder, and MECP2 positive, non-Rett individuals • Increased enrollment goal to 1350 • Principal sites: Children’s Hospital Boston, Baylor, Greenwood Genetic Center, and UAB • IRSF now provides support for Rett portion
Natural History Study • Current enrollment = 1093 participants • ~40% enrolled at travel clinics • Rett syndrome = 853 • Variant forms = 149 • MECP2 positive, non-Rett = 91 • Females = 46 (8 with MECP2 duplications) • Males = 45 (26 with MECP2 duplications)
MECP2 and Rett Syndrome! What we have learned • >95% of classic RTT have MECP2 mutations • 8 mutations account for ~ 60% • Deletion or insertions about 15-18% • Incidence: ~1:10,000 female births • Mainly sporadic: majority of paternal origin • Familial Rett syndrome is <<1% of total • Variant forms account for ~15% • MECP2 mutations in approximately 75% • And much more
The Future • New application likely in Fall 2013 • Restrict to MECP2 and related disorders • Rett syndrome; MECP2 duplication disorder; MECP2-related disorders: CDKL5, FOXG1, and MECP2-positive-non-RTT • Travel clinics to be phased out; addition of enrollment sites in Chicago, Denver, California, and Philadelphia
Future Goals • Improve early diagnosis • Expand biobank: X chromosome inactivation, whole exome sequencing, etc. • Develop and customize outcome measures • Expand clinical trials • Work with international sites to increase presence of uniform data collection and potential participants for clinical trials
Importance of SRSA • Continued role in promotion of research and recruitment of participants • Promotion of information exchange between basic and clinical research to facilitate translational research pipeline • Continued opportunities to meet with and update families on progress
Framing Regression • The point at which an individual loses, either partially or completely, previously acquired skills. • In Rett syndrome, regression is related to loss, partially or completely, of previously acquired skills in fine motor function and spoken language or communication.
What must be done? • If we are to begin treatment as early as possible, earlier diagnosis is required. • We need to make certain that primary care physicians are knowledgeable of and are empowered to diagnose RTT. • It is our responsibility as physicians, but IRSF and all interested individuals can make a major difference.
Steps to accomplish the goal • Provide information through the American Academy of Pediatrics • Stress the importance of this information on education and training programs in medical and allied health schools. • Work with public health agencies at local, state, and federal levels to spread the word.
Research in Critical Transition • Increase in individuals with RTT and other MECP2-related disorders • Animal models of human mutations • Single cell culture: neurons or glia • Tissue slices: specific brain regions • Stem cells: from human skin fibroblasts • Differentiated to neurons or glia or cell type of interest • Testbeds for research and drug discovery • No viable direct therapy……..YET
Prior Clinical Trials • Lamotrigine for seizures • Bromocriptine for motor performance • Naltrexone for periodic breathing • Folate-betaine to increase methyl-binding • Little benefit aside from improved seizure management with lamotrigine
Gene Therapy • Gene correction • Problem: Correcting only abnormal allele • Stem cell transplant • No effect in symptomatic male mice; some improvement in asymptomatic females • Noted positive response in microglia • Suggests role for pharmacologic approach • X chromosome activation of normal allele • Critical: activate normal allele in all cells
Symptomatic Therapy • Serotonin reuptake inhibitors • ameliorate anxiety • NMDA receptor blocker: Memantine • reverse glutamate hyperexcitability • IGF-1: full length and tri-peptide • downstream effect in BDNF cascade • BDNF mimetics: TrkB agonists • restore BDNF levels • Read-through compounds: Stop mutations • produce full length MeCP2
MeCP2 Restoration • Missense mutations: Reactivate full-length protein • Nonsense (Stop) mutations: Promote full-length protein; may require ‘reactivation’ • Deletions/insertions: More complicated – requires more thinking
The Team • Baylor College of Medicine • Daniel Glaze • Kay Motil • Jeff Neul • Judy Barrish • Greenwood Genetic Center • Steve Skinner • Fran Annese • Lauren McNair Baggett • NIH: ORDR/NICHD • CHB • Walter Kaufmann • Daniel Tarquinio • Katherine Barnes • Heather O’Leary • UAB • Alan Percy • Jane Lane • Suzie Geerts • Jerry Childers • Girls and women with RTT and their families