5/19/2014. The Genetics of AMD. Disclosures. Introduction. A marriage made in heaven. DNA, structure, function and variability

Transcription

1 DNA, structure, function and variability A marriage made in heaven The Genetics of AMD Steven Ferrucci, OD, FAAO Chief, Sepulveda VA Professor, MBKU/SCCO Diana Shechtman, OD, FAAO Professor, Nova Disclosures Computer code digitizes the world using only two variables DNA replicates by splitting Ferrucci Alcon Allergan Artic Dx MacuLogix Thrombogenics Shechtman Alcon Allergan Arctic DX B&L CZM ZeaVision Introduction DNA, the physical basis of inheritance, has 4 variables Single Nucleotide Polymorphisms Basic Genetic Primer Genetics of AMD Genetic tests Genetics in other fields Controversies RNA DNA Sometimes an error isn t detected and fixed, but is instead passed down to future generations. 1

2 SNPs are important markers of disease BRCA1 and BRCA2 Genes that produce Tumor Suppression Proteins Specific inherited mutations increase the risk of female breast and ovarian CA Together account for 20-25% of hereditary breast cancer, and 5-10% of all breast CA Approx. 15% of all ovarian cancer Colorectal Cancer 160,000 case of colorectal cancer diagnosed year 3-7% due to inherited condition known as Lynch Syndrome Greater risk for development of colorectal CA Younger age (< age 50) Greater risk of developing other cancers ( liver, brain, prostate) Also cancers associated with BRCA1 and 2 happen at a younger age Variations in the MLH1, MSH2, MSH6, PMS2, or EPCAM gene Genotypes Phenotypes At each locus (except for sex chromosomes) there are 2 genes. These constitute the individual s genotype at the locus. The expression of a genotype is termed a phenotype. For example, hair color, weight, or the presence or absence of a disease. BRCA1 and BRCA2 Breast CA: Women's lifetime risk of Breast CA 12% With BRCA 1, 55-65% by age 70 With BRCA2, 45% Ovarian CA: Lifetime risk of 1.4% With BRCA 1: 39% BRCA 2: 11-17% Even higher rates in certain populations Ashkenazi Jewish Colorectal Cancer Pts diagnosed with colorectal CA should be offered testing If a family member is found to be positive, other family members should be checked to see if at increased risk Increased frequency in screening for positive individuals Routine colonoscopies starting at age Women with Lynch disease should be encouraged to start family planning earlier 2-3% of women with Lynch disease develop ovarian CA by age 35 Pts are not strangers to genetics What entities are THEY most familiar with when it comes to genetics? BRCA1 and BRCA2 If found: Enhanced screening Start annual mammograms at age Prophylactic (Risk reducing) surgery Bilateral mastectomy Removal of fallopian tubes/ovaries Chemoprevention Tamoxifen (breast CA) Oral contraceptives (ovarian CA) Poor prognosis BRCA1 tend to respond poorly to current treatment Pharmacogenomics Genetics being used in other medical field to help determine Which drug is most appropriate Which drug might produce less side effects Offer drug that might work best Might save time and money No more trial and error 2

3 Pharmacogenomics Examples: HIV Medication Ziagen more likely to cause adverse effects with certain genetic variants Breast Cancer drug Trastuzumab (Herceptin) only works for women with a certain genetic profile that leads to overproduction a protein called HERS2 Tressa and Traceva only work in Lung CA pts with certain genetic makeup AMD is a Genetic Disease Those with stronger genetic risk develop more advanced disease earlier in life. RESOURCES WEBSITES Eyegene provides not only mutation analysis for the individual patient, but will keep DNA samples and make them available to researchers. Retnet.com availability around the world of genetic testing for the disease in query, and for a list of fee-for-service and of research laboratories LABS Carver Laboratory GeneDx Laboratory Genewiz Lab ARUP Lab corp Arctic Dx Nicox Pharmacogenomics Examples: Erbitux and Vecribix do not work in about 40% of pts with specific colorectal CA gene profile FDA recommends genetic testing before starting chemotherapy drug mercaptopurine (Purinethol) on pts with acute lymphoblastic leukemia and Colorectal drug Camptostar Excessive Weight Lack of Physical Activity Smoking Ocular genomics >500 genes have been linked to eye diseases 15 yrs of evaluation >850 inherited ocular diseases cal-descriptions You can get information on The particular inhered genes Clinical features (ocular & systemic) Treatment options Resources/references AMD is a genetic disease with known markers accounting for at least 70% of the population attributable risk In other words: AMD is >70% due to genetics! J.M. Seddon, B Rosner et al; IOVS May 2009 Ocular genetics WHY? Dx, tx, determine prognosis, counsel, research Ocular genomics Growing FOCUS Inherited retinal disease RP, XLRS, Cone dystrophies, Best s disease, SD The potential treatment lies on gene therapy Pattern dystrophies, Dominant drusen & ocular albinism Understanding clinical differences among mutations of similar genes Tumors 40% of Retinoblastoma are associated with inherited germline mutation ( + DNA testing) Only 5% of overall cases have (+) FHx Increases risk of pinealblastoma Anterior segment diseases Corneal dystrophies aniridia,, congenital cataracts, A-R syndrome OTHERS Glaucoma, color blindness, optic atrophy, phakomatoses (RCH) AMD 3

4 How do we find AMD? Must start with clinical exam What exactly is the minimum findings to qualify for AMD? In the beginning Gene Found to Increase Risk of AMD 4 independent research teams (including NEI) discovered a gene that is strongly associated with the development of AMD Gene is called Compliment Factor H CFH gene produces a protein that helps regulate inflammation in part of the immune system that attacks diseased and damaged cells To date there s been 100 s of studies covering 177K pts CHOLESTEROL TIMP3 AMD Genes Attributed risk may vary ND2 by ethnicity CFH CFH: Largest attributed risk (26%) C3 Complement CFI (inflammation) C2BF ARMS2 Oxygen ND2 ARMS2: Metabolism LIPC 2 (oxidative stress) CETP attributed Cholesterol LPL risk (22%) ABCA1 (HDL) TIMP3 Vessel Formation (VEGF) C2BF CFI C3 CFI Macula Risk New Genes under Review 29% Non-Genetic Heritability of Advanced AMD 71% 1 Genetic Genetics has an extremely high influence on the risk of developing and progressing to advanced AMD (for comparison): Obesity 54% CVD 49% Prostate cancer 42% Breast cancer 27% Type 2 diabetes 26% Since then a # of other genes have been identified Gene affecting different pathway may influence progression (Yu IOVS 2012) N=genetics of 2600 pts were evaluated for prevalence or progression towards AMD Results LIPC & ABCA1 associated with decreased risk of progression form normal to intermediate CFH, C3, CFB, and ARMS2 were associated with progression from intermediate 1) : Seddon et al. The US twin study of age-related macular degeneration: relative roles of genetic and environmental influences. Arch Ophthalmol Mar;123(3): Some of the Main Players CFH (Complement Factor H) The complement cascade is responsible for primitive inflammation ARMS2 (Age Related Maculopathy Succeptablility 2) Plays a role in the excretion of oxygen free radicals ND2 A gene that controls mitochondrial oxidative stress through their role in oxidative phosphorylation C3 (Complement Cascade Component 3) Mediates inflammation and cell health: Increases sensitivity of CFH risk Additionally, Cholesterol metabolism plays a role, and there are 4 gene variants TIMP3: Tissue Inhibitor of Metalproteinase Genetic testing 2009: For the first time ever, an individual's inherent risk of developing this devastating eye disease can be determined Available 2011 Niciox bought rights

5 2 forms of RetnaGene: AMD & LR Macula Risk NXG How the pt gets tested Intended to assess a patient s risk of progression to CNV within 2, 5, and 10 years For patients with mild to moderate AMD Delaying progression with secondary prevention including vitamins, modified surveillance, etc. Intended to assess a patient s absolute and relative lifetime risk of developing advanced AMD (GA or CNV) For patients with a family history of AMD or who are over the age of 55 Delaying onset of disease with primary prevention including lifestyle modifications and nutritional intervention Next generation takes into account: genetic polymorphism along w Age, BMI, (+)Smoking, Clinical AMD status to Stratified AMD patients that progress odds towards Adv stage of dz (associated with VL) a 10yr Predictive Value of ~90%* CLIA waiver low risk of problems associated w Procedure & low FP/FN 20 swipes` RetnaGene by Sequenom Also cheek swab done in office 12 SNiP s along with age, smoking and phenotype Test only VADILATED for pts with disease to evaluate progression Prospective Assessment of Genetic Effects on Progression to Different Stages of Age- Related Macular Degeneration Using Multistate Markov Models Yi Yu IOVS weeks RetnaGene Publications (Ophthalmology) Thought process READING THE REPORT Inclusion of Genotype with Fundus Phenotype Improves Accuracy of Predicting Choroidal Neovascularization and Geographic Atrophy Purpose: Determine if the addition of patient genotyping improves accuracy of risk prediction over an assessment based on disease stage alone 2,415 patient DNAs genotyped 14 SNPs assessed 12 SNPs strongly associated with the development of CNV 1 Performance of Phenotype + Genotype Model outperformed Phenotype alone 1. Hageman GS, Gehrs K, Lejnine S, et al. Clinical validation of a genetic model to estimate the risk of developing choroidal neovascular age-related macular degeneration. Hum Genomics 2011;5: ,106 Patients 11.1 Years Model Risk factors Predictive Accuracy Non-genetic risk Age + Sex + BMI + Smoking + model AMD status 78% Genetic model Age + Sex + Genetics 82% Combined model (non genetic + Age + Sex + BMI + Smoking + 88% genetics) AMD status + Genetics You Must Consider All Risk Factors AMD Status, BMI and Smoking --- Predictable Risk factors 2, 5 and 10 Year Risk of Progression Macula Risk Score Genetic Risk Subscore 66% = that only 1/3 of the normal population will have a higher genetic risk factor; while 2/3 of population have lower risk Results: Predicted Risk of CNV Based on Phenotype + Genotype Genotype Reveals Individual Differences Average Risk of CNV Individual Risk of CNV In In Grade 4 Subjects Grade 4 Subject With Without Genetic Information Genetic Information 65% C-Statistic for Phenotype Only C-Statistic for Phenotype plus Genotype 0.89 (CI ) 0.96 (CI ) 90% 30% Patient Sampling 1. In office saliva test / cheek swab; 2. No refrigeration; 3. No hazardous material (transportation issues); 4. Recommend gloves for Technicians 5. NO CLIA form necessary 6. Inform consent Macula Risk Score Macula Risk 3, 4 & 5 = 20% of the Caucasian population Conversion of AMD 1% 2.2% 16.8% 50% 30% Average Population MR1 MR5 may help with follow-up: q12m-5x/yr Test was validated to evaluate progression of dz not to determine Who will get disease 5

6 Intended for pts w signs of disease Reimbursement: Cover with?$20 co-payment ICD-9 Codes non-specific AMD; nonexudative senile macular degeneration exudative senile macular degeneration drusen problems No Reimbursement ($450) No insurance No diagnosis of AMD or drusen Sequenom testing billed directly to pt Vitreal floaters (PVDs) Follow-up at 3M: No reported visual changes OD 20/25, OS 20/30- Testing is meant for pt with FINDINGS Assessing risk of VL and advancement toward the end stage of disease. BOTTOM line genetics help with surveillance Genetic testing vs No Testing American Society of Retina Specialists Annual Meeting August 2013 Peter Sonkin MD, Tennessee Retina Assessment Dry AMD OU HRT OD Plan Macula Risk test perform today Return 1 month for test results & OCT Letter to PCP with regards to HTN Pharmacogenomics Tezel ARVO Genetic Risk Factors for Age-related Macular Degeneration (AMD) can be Predictive for the Functional and Anatomical Outcome of Intravitreal Anti- VEFG tx The presence of high risk alleles of CFH, C3, ARMS2, ND2 indicate a poor response to AVT. Pts expressing high-risk alleles require higher number of intravitreal injections to reach anatomical stability and are associated with poorer visual outcome. Multiple small studies (n >50) Genetic factors associated w response to Lucentis in pts w Wet AMD. Park Retina 2014 Patients genotyped for 23 SNP w/i 12 AMD-relevant genes. For each polymorphism, genotypic association with good response at Month 5 50% were good responders. No tested polymorphism showed statistically significant association with favorable visual outcome at Month korean pts Applying genetics in your office 69 year old white male Lifetime smoker 1+ packs per day PMHx: HTN BP: 157/89mmHg RAS BCVA OD 20/25, OS 20/20 Follow-up 1M MR4 results discussed Plan OD 20/25, OS 20/20 Recommend an AREDS product RTC 3 months for OCT and Exam (Given the MR results) Evaluated the association of SNP in VEGF genes and their receptors (VEGFR) with the response rate to lucentisn= SNP in the VEGFR2 significantly affected VA outcome This study shows, THAT IN PART, genetic variation may be explained The variation in tx response 54 6

7 Diets high in antioxidant properties were found to reduce the risk of development of early AMD in persons who had high genetic risk for developing AMD Nurture >>nature (N> 2,000 responded to food freq Qs) Higher dietary intake of zinc, omega-3 fatty acids, beta-carotene, and lutein/zeaxanthin delayed onset of EARLY AMD The other side of the coin Klein Ophthalmology 2008 Retrospective analysis of participants form AREDs study Supplementation was associated with a greater reduction in AMD n=>800 progression DNA (68%) evaluated in those who with had the low-risk AREDS genotype >3 compared with those with the high-risk genotype (11%) category and look for snp of ARMS2/CHF Goal; evaluate interaction b.t the above genetic variant & respond to AREDS Results: Progression occurred in 264 Interaction observed b/t CFH & AREDS with antioxidants plus zinc B.t pts taking Zn (compare to NO Zn) & CFH No interactions observed for ARMS2 First do no harm. Zinc can cause harm to some.determined by genetics Although for ~12% Zinc alone was best, ~64% should NOT get zinc!!!!! (about 29% do as well with NOTHING as with anything) Individualize care based on genotype (not just phenotype) The dawn of pharmacogenetics in eyecare! High Genetic Risk Patients Can we eat away the genetic risk for AMD? ARMS2 A69S (rs ) Benefits & risk of supplementation may depend on the AMD genes of the pt Zinc is detrimental in High risk CFH allele Best to use antio alone (red line) in these pts Individuals with highest Zinc + EPA/ DHA in their diet (3 rd tertile) could compensate their genetic risk from ARMS 69S Ho et al. Reducing the genetic risk of age-related macular degeneration with dietary antioxidants, zinc, and ω-3 fatty acids: the Rotterdam study. Arch Ophthalmol Jun;129(6): CONFIDENTIAL 56 In pts with HIGH risk allele within 12 yrs: the risk of AMD progression was 73% of those who took Zn w/ or w/o AREDS worsen (green/purple) 38% of those who took AREDS NO Zn (red) High Genetic Risk Patients Can we eat away the genetic risk for AMD? CFH Y402H (rs ) s ARMS2 High-Risk Alleles have WORSE outcome if take antio taken & thus, Zn alone is best lowest progression towards AMD (green line) There s different impact BOTH CFH/ARMS2 are affect NEITHER CFH/ARMS2 are affect This is emerging science Epigenomics Individuals with highest Zinc + beta-carotene in their diet (3 rd tertile) could compensate their genetic risk from CFH 402H using food frequency questionnaire Ho et al. Reducing the genetic risk of age-related macular degeneration with dietary antioxidants, zinc, and ω-3 fatty acids: the Rotterdam study. Arch Ophthalmol Jun;129(6): % of patients derive more benefit from a formulation other than AREDS. For 23% of patients, the AREDS formulation was the best treatment Zinc Zinc + AntiO Placebo AntiO CONFIDENTIAL 57 7

8 Example: A pt in your office What would you recommend for this patient? Not so fast, don t you want to know genetics? Genotype Directed Eye Vitamin Formulations 10 Manufacturers of AREDS Formulations for Macula Risk AAO stand on AMD & genetic testing AMD is a complex diseases People may have the risk alleles but not the disease o a statistical association between particular risk factors the predisposition to certain diseases, especially when those factors are combined with environmental risks. For this reason, routine genetic testing for genetically complex disorders is not recommended until tx or surveillance strategies have proved to be beneficial in one or more published clinical studies. How do you calculate vitamin risk? Do best with antio alone High risk CFH allele The controversy: NEI stand on Awh paper Data only took into account N=1,ooo o information was derived on trends & models from this original data Dr. Chew and colleagues were not able to reproduce SAME data when they analyze the group The Controversy Continues CFH and ARMS2 represent rather a unique example in complex traits as these two susceptibility loci alone contribute substantially to the AMD heritability. o This has resulted in occasional success with risk prediction and progression in few studies. o However, these approaches lack the sensitivity and specificity with most of the individuals having middle range of AMD risk and thus have little diagnostic value There are multiple additional genes with small effect size on AMD susceptibility o Thus testing genetic risk using single susceptibility gene variants will have limited predictive value Have to use both phenotype and genotype in judgment of appropriate treatments and f/u Individualized analysis and treatment is what each patient deserves More controversy: Should we test early AMD pts? Risk Alleles in CFH and ARMS2 and the Long-term Natural History of ARMD. JAMA OPHTHALMOL For now, knowing the phenotype when early AMD is present contributes more to risk assessment than knowing the genetic risk based on the 2 AMD candidate genes with the largest attributable risk. Recommendations for Genetic Testing of Inherited Eye Disease Offer genetic testing to patients with clinical findings suggestive of a Mendelian disorder whose causative gene(s) have been identified Use Clinical Laboratories Improvement Amendments approved laboratories for all clinical testing. Provide a copy of each genetic test report to the patient so that she or he will be able independently to seek mechanism-specific information Avoid direct-to-consumer genetic testing and discourage patients from obtaining such tests themselves. Avoid unnecessary parallel testing order the most specific test(s) available given the patient s clinical findings. Avoid routine genetic testing for genetically complex disorders like age-related macular degeneration and late-onset primary open-angle glaucoma until specific treatment or surveillance strategies have been shown in 1 or more published prospective clinical trials to be of benefit to individuals with specific disease-associated genotypes. Avoid testing asymptomatic minors for untreatable disorders except in extraordinary circumstances. 8

9 Recommendations for Genetic Testing of Inherited Eye Disease Avoid routine genetic testing for genetically complex disorders like age-related macular degeneration and late-onset primary open-angle glaucoma until specific treatment or surveillance strategies have been shown in 1 or more published prospective clinical trials to be of benefit to individuals with specific disease-associated genotypes. Genetic Information Nondiscrimination Act of 2008 GINA does not apply to employers with fewer than 15 employees. US military. Health insurance through the TRICARE military health system, the Indian Health Service, the Veterans Health Administration, or the Federal Employees Health Benefits Program. Lastly, the law does not cover long term care insurance, life insurance or disability insurance. Treatment response May have implications regarding treatment 37% higher risk of additional Lucentis injections if CFH Y402H CFH TT/TC treated with Avastin had increase in vision with 53.7 % improved vs. only 10.5% if CC genotype VEGFR2: 2 seperate SNPs associated with increased response to Lucentis CATT study did not show relationship between genetic subtype and treatment Controversies Worry patients unnecessarily False sense of security Over treat some patients Undertreat others Financial/employment/insurance concerns Genetic Information Nondiscrimination Act of 2008 GINA tasks the Equal Employment Opportunity Commission with protecting workers from genetic discrimination in the workplace. According to the EEOC: 726 charges have been filed under GINA as of September In May 2013 the Commission announced the settlement of the first lawsuit it had filed for a GINA violation (EEOC v. Fabricut Inc.) and the filing of a second suit (EEOC v. Founders Pavilion Inc.) Genetic Treatment If defective gene responsible for abnormal VEGF expression can be localized, perhaps a replacement, or fixer gene can be injected into the eye ONE TIME! Genzyme AAV2.sFLT01 Avalanche Biotechnologies AVA-101 Oxford BioMedica RetinoStat Genetic Information Non-discrimination Act of 2008 Protects individual in Both health and employment Title 1 prohibits issuers of health insurance from discrimination on the basis of the genetic information of enrollees. issuers may not request or require individuals or their family members to undergo genetic testing or to provide genetic information. Title 2: prevents employers from using genetic information in employment decisions such as hiring, firing, promotions, pay, and job assignments. prohibits employers or other covered entities from requiring or requesting genetic information and/or genetic tests as a condition of employment Personalized Medicine Each of your patients is an individual with their own potential needs This is the beginning of the end of worshiping at the altar of the large randomized placebo-controlled clinical trial. It introduces the era of personalized medicine based on, among other findings, genetic profile. Leo Semes, O.D., F.A.A.O. Summary Knowledge of genetic risk is important Increased counseling for patients at high risk Know which patients need to be examined more frequently Sooner/correct vitamin supplementation May have implications regarding response to treatment May guide future treatments 9

10 Thank you! 10