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U.S. – Russia Scientific Forum Rare Diseases Examples from the Intramural NIH: Oculocutaneous Albinism Undiagnosed Diseases Program David Adams, MD, PhD.

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Presentation on theme: "U.S. – Russia Scientific Forum Rare Diseases Examples from the Intramural NIH: Oculocutaneous Albinism Undiagnosed Diseases Program David Adams, MD, PhD."— Presentation transcript:

1 U.S. – Russia Scientific Forum Rare Diseases Examples from the Intramural NIH: Oculocutaneous Albinism Undiagnosed Diseases Program David Adams, MD, PhD National Human Genome Research Institute National Institutes of Health

2 The NIH Intramural Program The National Institutes of Health – 90% of resources  Universities, extramural grants, other initiatives – 10% of resources  The NIH Intramural Program Large research campus near Washington, DC The NIH Clinical Center—a hospital dedicated to clinical research. Study participants brought to the NIH to participate in collaborative research on rare and common illnesses Provides a mechanism to see families with rare conditions who may be spread out over country/world

3 Two Examples Oculocutaneous Albinism The NIH Undiagnosed Diseases Program Both studies – Combine the clinical and research expertise of the NIH community – Provide mechanisms for collaborations with researchers inside and outside the intramural program – Focus on rare, ultrarare and/or new diseases

4 Oculocutaneous Albinism Worldwide/pan-ethnic ~1:20,000 An important cause of inherited visual impairment Primary manifestations are skin/hair hypopigmentation and decreased visual acuity wikipedia

5 OCA Genetics and Mechanism Syndromic Types (Hermansky Pudlak Disease, Chediak Higashi Disease) Non-syndromic types – Four known genes cause OCA – One known gene causes OA Defect in melanin production or melanin intracellular transport OCA Type 1: Tyrosinase OCA Type 2: OCA2 protein OCA Type 3: Tyrosinase- related protein 1 OCA Type 4: SLC45A2 solute carrier In OCA, ~20% of cases will not have 2 mutations in any of these genes.

6 Tyrosinase Biochemistry

7 Eye Abnormalities in Albinism Foveal Hypoplasia Reduced cone density Reduced visual acuity From Wikipedia “fovea”

8 OCA Natural History Study Recruit OCA Participants Ophthalmology Clinical Data Collection Acuity Testing Coherence Tomography Evoked Potentials Retinal Photographs AudiologyScreening Spatial Processing Examination/History Adaptation to Low Vision Skin Reflectometry Bio Materials Collection Melanocytes/Fibroblasts Plasma/Serum Photographs/Family Photographs DNA/RNA Low Vision OT Molecular Sequencing Deletion Confirmation DNA Variant Characterization Database Cell Biology Immortal line development In vitro assays Basic Science Investigations

9 Ongoing OCA Projects ProjectCollaborators Developing clinical trial for a novel therapeutic agent that increases tyrosinase substrate (tyrosine) and may increase melanin production in eyes and other tissues. Brooks Genotype/phenotype correlations by in silico modeling of tyrosinase variants. Sergeev Understanding the cell biology/functions of OCA2 and OCA4 gene products. Hearing Determining causes of OCA when there are no or insufficient mutations in known OCA genes. Wang, Gahl Laboratory

10 NIH Undiagnosed Disease Program Primary Goals – To provide answers to patients with mysterious conditions that have long eluded diagnosis – To advance medical knowledge about rare and common diseases Participants Travel to NIH for Extensive Diagnostic Evaluation – Started in 2009 – >5000 inquiries, >400 study participants seen – Diagnostic and research tools utilized

11 Records Received

12 Solved Example: NT5E NEJM 2011 364:432

13 Solved Example: Amyloidosis

14 Unsolved Example: Progressive Neurological Disorder in a Child Normal early development Type I Diabetes diagnosed at 3 ½ y/o Vocal Tremulousness Steadily progressive weakness, dystonia – Right-sided then generalized

15 Unsolved Example: Granulomatous Skin Disease

16 Research vs Clinical Approach to Disease Clinical Approach – Broad range of consultants in one place – Extensive inpatient evaluation and history taking – Extensive review of prior records Research Approach – In house and collaborative follow up of diagnostic leads – Application of tools for agnostic screening, e.g. Metabolic (cell oxidation, microscopy, mass spec.) Genetic (whole genome, exome, transcriptome seq.)

17 Next Generation Sequencing Example: Exome Sequencing – Sequences large subset of all known genes – Rapid improvements in cost, data quality – Benefits Allows multiple genetic hypotheses to be explored – Challenges 10 4 – 10 5 DNA sequence variants per case Many false positives, some false negatives Variants must often be verified experimentally

18 NGS Method Development Application to non-optimal cases – No known consanguinity/regions of homozygosity, linked regions – Small families (too small for linkage analysis) or individuals Optimization of strategies to sort/filter variants Low threshold for establishing collaborations for functional validation of potential disease- causing variants by subject experts

19 NGS Example: KCTD7

20 NGS Example: FA2H Combination of SNP array analysis and NGS detects missense mutation paired with small deletion a A Aa AA

21 Hardest Problem  Validation

22 Summary The NIH intramural program combines basic and clinical research Two examples of rare-disease research – Oculocutaneous Albinism Studies aimed at understanding clinical, cellular and genetic aspects of inherited pigmentation disorders – Undiagnosed Diseases Program Study conditions that have long eluded diagnosis Aadvance medical knowledge about rare and common diseases

23 Summary “…when there is teamwork and collaboration, wonderful things can be achieved.” Mattie Stepanek

24 Acknowledgements and Contact Information The NIH Undiagnosed Diseases Program – William A Gahl, MD, PhD, Director The NIH National Human Genome Research Institute The many families who partner with us to advance the cause of rare disease research David Adams: david.adams@nih.govdavid.adams@nih.gov For an updated copy of these slides, go to: ftp://ftp.nhgri.nih.gov/pub/NIHUDP/MOSCOW2011/presentation.pdf


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