Enviromics By: Larry Burd, Ph.D. Professor, Department of Pediatrics Director, North Dakota Fetal Alcohol Syndrome Center University of North Dakota, School of Medicine and Health Sciences Grand Forks, ND

Enviromics: The study of environmental effects

Phenomics EnviromicsGenomics Concepts

EnviromeEnviromicsExposures n = thousands GenomeGenomicsDNA n = thousands Transcriptomics RNA all n = thousands ProteomeProteomicsProtein all n = thousands MetabolomeMetabolomicsBiochemicals n = hundreds Phenome Phenomics Phenotype

Enviromics Exposure Dose Action Effect Size Genomics DNA RNA Protein Effect Size

Exposure Dose Effect Effect Size DNA RNA Protein Metabolites Phenotype Enviromics Genomics

Enviromic Components Models Exposures Prevalence Effect Magnitude Timing Interactions Confounders Phenotype Variance

Variance in Phenotype (Vp) Variance in Genetic Factors (Vg) Variance in Environmental Factors (Ve)

Variance in Phenotype Vp = Vg + Ve Modeling Variance Estimates Vp = Vg + Ve Ve = Vp – Vg Vg = Vp - Ve

Enviromics Casual Effect Modifiers No Known Effect Confounders Interactions

Dosiometry

Fetal Maternal Organ System Function/Behavior

Exposure 0 High

EXPOSURE: Units/Dose Cigarettes 1. # per day 2. Total Exposure 3. Cotine level per trimester of pregnancy Head Injury 1. # of events 2. Time in coma Genetics Duplication Trisomy 21= Syndromal Variablity Expansion – Repeats Trinucleotide repeats Fragile X= Mental Retardation IQ Mytonic Dystrophy = Age Onset Rate Progression Imprinting Gene Silencing= RNA Phenotype Expression

Smoking: Weekends Packs OCC ++ X Chart Data

10 1 packOcc 7-15 lightheavy Has cut down Smoking: Chart Data

Alcohol: X Y - - Chart Data

Alcohol 2 day3 – 4weekend Quitcut down Needs treatment? 2 DUI’s * Chart Data

Units of Exposure 0 High Drinks day week binges (4/5) pregnancy BAL Cigarettes day week pregnancy cotine levels

Threshold 0Exposure Dose High Outcomes Severe Protective

Linear non-Threshold Outcomes Severe 0Exposure Dose High

Hormetic Outcomes Severe 0Exposure Dose High

Each Exposure Should be Considered an Episode Temporal parameters Dose

Profile of Exposure Episodes

Physiologically based pharmacokinetics model (PBPK) Genes “+” condition 2, 3, or 4 hit model Genetic predisposition Developmental stage Exposure Interaction

Elimination Kinetics Absorption Distribution Metabolism Excretion

Exposure Assessment and Phenotype Detectability are Interdependent

Phenotype Severe Absent

Phenotype Detectability Severe Absent

Severe Absent Phenotype Severe Absent Detectability Phenotype Detectability

Coherence Threshold Sensitivity Specificity Positive predictive value Negative predictive value Accuracy Dose Phenotype

Exposure and Phenotype are linked. Dose Detectability 0 High Absent High

Phenotype Prevalence or Severity 0 Excess Costs Cost Savings Cost of Exposure Exposure/Dose

Phenotype Prevalence 0 Excess Costs Cost Savings Unitize: Exposure Prevalence Severity Costs = Cost per outcome or Costs = per unit of exposure Cost of Exposure

Detection Classification Phenotype Detectability

Detection Sensitivity Low Mortality High Testing & Control Group Normal Tests Observation & Testing Observation Syndrome Mortality Increased prevalence of signs Syndrome and comorbidity Typical Syndrome Exposure (Dose) Severe Syndrome Mild NOAEL None TOEL Typical LD – 50 Lethal LOEL Low

Disease Status +- True positives = TP+TN+phenocopies * ___ 100% False positives = FP+FN+phenocopies † ___ 100% False Negatives = FN+TN+phenocopies * ___ 100% True negatives = FP+TP+phenocopies † ___ 100% *Diagnosis with no exposure; † exposure without diagnosis. TP = true positives; TN = true negatives; FP = false positives; FN = false negatives Diagnostic Status +-+-

Exposure vs. Significant Exposure NOEL No Observable Effect Level LOAEL Lowest Observable Adverse Effect Level TAEL Typical Adverse Effect Level: 50% with adverse outcome at exposure level LD – 50 Lethal Dose for 50% exposed

Susceptible Exposed Unexposed

Adverse Outcomes Due to Prenatal Alcohol Exposure Did mom drink? Did she drink enough? Abnormal signs or disorders? Yes or No Was Alcohol a contributor to outcome?

SCREENING FOR ALCOHOL ABUSE TWEAK Test (Russell 1984) TOLERANCEHow many drinks can you hold? If more than 5 drinks = 2 points WORRYHave close friends or relatives worried or complained about Your drinking in the past year? Yes = 2 points EYE-OPENERDo you sometimes take a drink in the morning when you first get up? Yes = 1 point AMNESIAHas a friend or family member ever told you about things you said or did while you were drinking that you could not remember? Yes = 1 point K/CUT DOWNDo you sometimes feel the need to cut down on your drinking? Yes = 1 point A score of 2 or above places the woman in a risk category and requires further assessment.

Estimating Dosage Fetal Drinks per drinking day Days per week Binge days 1 st Trimester Last Trimester At labor and delivery Cumulative dose

Estimating Dosage Maternal Cumulative (Lifetime) Drinks per drinking day 1 st drink 1 st drunk 1 st treatment 1 st pregnancy Each treatment Each pregnancy

Alcohol Binges Total Dose Days Exposed Genetics Age Education Diet Smoking Birth Order Previously Affected Child Paternal effects Necessary but not sufficient Critical Susceptibility Components Dose Duration Timing Exposure

Cumulative Dose to Event

Assessment of Exposure During Pregnancy On average how many days per week did you drink during pregnancy? _____(a) What is the most you had to drink on any one day during pregnancy? _____ On an average drinking day during pregnancy how many drinks did you have? _____(b) Exposure Parameters (Cumulative exposure during pregnancy)  Pregnancy Drinking Days = ( a x 40 ) = _____(c)  Estimate of number of drinking days during pregnancy.  Percent of Days Exposed During Pregnancy = ( c ÷ 280 ) =  Estimate of days exposed during pregnancy. _____  Number of Drinks During Pregnancy = ( a x b x 40 ) =  Estimate of number of drinks during pregnancy. _____(d)  Ounces of absolute alcohol = ( d ÷ 2 ) = _______  Estimate of exposure to absolute alcohol during pregnancy.

FASD Phenotypes

Exposure Adverse outcome Expression Threshold Phenotype Severity Mortality LD - 50 Synergistic Effects Concept:

Synergistic Effects Application: Exposure Heart Defect Mortality

Modeling Exposure Outcomes

Exposoure High Low ARND FAS Fetal Stillbirth Infant Death Mortality Outcomes

Exposure High Low Fetal Stillbirth Infant FAS ARND Death Mortality Outcomes

Exposure High Low Fetal Stillbirth Infant FAS ARND Death Mortality Outcomes

Concluding Thoughts Phenotype and Exposure are Linked Exposure dose Exposure profile Phenotype detectability Dose – phenotype Refinement of measures