Explorations in regime change: -Thalassaemia and the interplay of technological change & social...
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Transcript of Explorations in regime change: -Thalassaemia and the interplay of technological change & social...
Explorations in regime change: -Thalassaemia and the interplay of technological change & social norms.
Zosia Bornik & Hadi DowlatabadiUniversity of British Columbia
with thanks to:Sue Cox, Peter Danielson, Ed Levy and Bernadette Modell
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Overview
• Objective of this research• Definitional issues. • Domain information.• Findings.• Conclusions/more
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Objective
• At UBC:– Study democratic issues related to applied
genomics.
• At CMU:– To explore features of regime change.
• Synthesis:– What might drive shifts in social norms?
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Social Norms
• As a noun:– It describes how a peer group shares specific values
and hence chooses among a set of options.
• As a verb:– It is used as an approach to risk communication and
intervention. It has been successfully employed to address excessive drinking among college students…
• Recent History:– Based on research by Alan Berkowitz and H. Wesley
Perkins working at Hobart and William Smith Colleges.
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A two-level model of behaviour
• Norm based heuristics:– “There are the values we hold”
• Deliberated decision:– “I know what is valued and estimate the
benefits of this to outweigh its costs …”
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The question:
• What makes the higher level of decision-making be revised?
• Changing circumstance:– Social– Economic– Technologic– …
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An example:Thalassaemia
• Thalassaemia, is an inherited condition where the genes controlling haemoglobin production are affected.
• Each hemoglobin molecule contains four subunit proteins (2x and 2x). – Hemoglobin properly binds and releases oxygen only
when two alpha subunits are connected to two beta subunits.
– A pair of genes located on chromosome #16 controls the production of the alpha subunits of hemoglobin.
– A single gene located on chromosome #11 controls the production of the hemoglobin beta subunit.
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Its in the genes
-globin genes -globin genes
Chromosome 11 Chromosome 16
Hemoglobin Protein
b1
b2
a1
a3
a2
a4
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-Thalassaemia
• When the -globulin genes (or their neighbours) are defective or absent, the patient suffers from -Thalassaemia of different severities. – Minor: where haemoglobin production is slightly
affected – Intermedia: …– Major: where both genes are affected leading to
severe anaemia.
• Patients with -Thalassaemia major need:– chronic blood transfusions
• AND– Chelation therapy (to address iron over-load)
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14/01/04
Clinical intervention
1. Diagnose anaemia2. Test for -trait using haemoglobin
electrophoresis3. Blood transfusions4. Iron-Chelation therapy
• ≥2 units of blood/mo.• Liver, heart & other medical problems
• ≥15 days/mo. of Chelation therapy
• Life expectancy: ~ 60yrs • Cost: CDN$1-2 M
Source: Zeuner et al, 1999
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Social intervention
1. Identify potential carriers2. Give them genetic counselling3. Bring pressure to avoid pregnancy
• Revised norms on procreation• Cost: CDN$ 6-100/cap
Source: Zeuner et al, 1999
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Genomic interventions
1. Test the genes:• Pre-natal
2. Give genetic counselling
3. Offer termination of pregnancy
• Revised norms on abortion
• Cost: CDN$ 150-1000/test
1. Test the genes:• Pre-implantation
2. Give genetic counselling3. Try in-vitro fertilization
again
• Revised norms on eugenics
• Cost: CDN$ 4000-5000/test
Sources: Verma 2003, Karczeksi 2003
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The Thalassaemia Belt
• 2-18% of the population consists of carriers (WHO, 1994)– includes Mediterranean Region, Middle East, Indian Subcontinent,
and Far East• Population movements have led to dissemination of the
gene…– ß-Thal now widespread in Europe, Americas and Australia. In 2002:– ~ 240 million healthy carriers worldwide.– ~ 200,000 ß-Thal major births per year (Cao et al, 2002).
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Fall in Thalassaemia Major with screening
Source: Modell
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The choices made in Cyprus
• 4% chose a different marriage partner.• 20% chose a smaller final family size.• 76% had selective abortion.
Source: Modell
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Fall in Thalassaemia Major Births
Source: Modell
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Uptake of pre-natal diagnosis by ethnic group (UK)
0%
20%
40%
60%
80%
100%
Cypriot Indian Pakistani Other
1st Trimester 2nd Trimester
Source: Modell
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High infant mortality
DiagnosisTransfusio
nservices
TechnologicalChange
Desferri-oxamine
Genetic screening
Improve infants
survival
Improve child
survival
Some get blood transfusions
Control health
spending
Some get Iron Chelation therapy
Revise social norms
Most are not born
SocialChange
Typically 150/1000 IM drops to ~
40/1000 of which 17% are ß-Thal major!
IM drops by another ~7/1000
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Why was Cyprus so successful?
Cyprus:• Genetically
homogeneous population 2-3 mutations.
• High prevalence rate 14% carrier rate.
• Broad public engagement through church, schools and community.
Elsewhere:• Genetically heterogeneous
(e.g., >23 mutations in Iran).
• Lower prevalence rate (and priority).
• Dominated by other concerns/norms.
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Conclusions
• When pressure is sufficiently high norms can shift (i.e., Cyprus, Italy, Iran).– Perhaps such shifts are more readily
accepted because they also address other objectives.
• Pressure to “preserve norms” (itself a norm at a higher level) trumps where population is heterogeneous(i.e., UK).
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Clinical Intervention costsfrom Zeuner et al, 1999Average life expectancy = 63 yearsTotal lifetime treatment costs for B-thal major = 490,000 British pounds
= 123,000 at a 6% discount rate (includes diagnosis, blood transfusion, outpatient visits, costs assoc w/ complications)
For costs incurred over different life stages, see Table 33, p.68
Social Intervention costsfrom Zeuner et al, 1999Total antenatal screening programme costs per 10,000 population group
= 33,869 – 800,060 British pounds(see CB analysis and Table 55, p. 90)
(includes carrier screening, counseling, pre-natal Diagnosis, and abortion)
Genomic Intervention costsCost for Pre-natal Diagnosis depends on countryIndia = 150$ Canadian per case (Verma, 2003) USA = 1000$ Canadian per case (Karczeksi, 2003)
Predicted costs for Pre-implantation Genetic DiagnosisUSA = at least 4000-5000$ Canadian per case (Karczeksi, 2003)