From family history to the From family history to the epigenetics of epigenetics of osteoporosisosteoporosis

National Osteoporosis Society Conference National Osteoporosis Society Conference Birmingham November 2016Birmingham November 2016

Dr Trevor ColeDr Trevor ColeConsultant in Clinical and Cancer Genetics West Midlands Consultant in Clinical and Cancer Genetics West Midlands

Regional Genetics Service and Birmingham Health Partners Regional Genetics Service and Birmingham Health Partners AndAnd

Honorary Reader in Medical Genetics University of Honorary Reader in Medical Genetics University of BirminghamBirmingham

Trevor.cole@bwnft.nhs.ukTrevor.cole@bwnft.nhs.uk

In Clinic ResourcesIn Clinic Resources• Professor Neil Gittoes – Consultant EndocrinologistProfessor Neil Gittoes – Consultant Endocrinologist

• Sue Stewart – Clinical Nurse SpecialistSue Stewart – Clinical Nurse Specialist

• Dr Trevor Cole – Consultant Clinical GeneticistDr Trevor Cole – Consultant Clinical Geneticist

• DEXA scanning (not for all appointments)DEXA scanning (not for all appointments)

• Strong links with BCH and transitionStrong links with BCH and transition

Types of OsteoporosisTypes of Osteoporosis

Primary Secondary

Type 1

Type 2

Type 3

Where do the genetic Where do the genetic factors act on BMD and factors act on BMD and

fragilityfragility

Bone Acquisition

Bone Loss

Genomic-Wide Association Studies Genomic-Wide Association Studies (GWAS) and Heritability Studies(GWAS) and Heritability Studies

Mitchell and Yerges-Armstrong Review 2011Summarised 10 GWAS papers

29 Loci “robustly” associated with BMD

These single nucleotide polymorphism accounts for only about 2-6% of variance in spine and femoral neck BMD

By definition each SNP associated with variance in one direction the opposite SNPwill be associated with the opposite effect

What are Single nucleotide What are Single nucleotide Polymorphisms (SNPS)Polymorphisms (SNPS)

A T C G T T T C G C T A ……………………….. GENE OF INTERESTT A G C A A A G C G A T

A T C G T T G C G C T A ……………………….. GENE OF INTERESTT A G C A A C G C G A T

“SLIGHTLY GREATER CHANCE”

“POPULATION CHANCE OR EVEN REDUCED CHANCE

SNP’s may be away from the possible candidate gene or even if within the gene may not have detectable effect on gene function

Will these SNP’s be clinically Will these SNP’s be clinically significant?significant?

Patient 1

Patient 2

Genomic-Wide Association Studies Genomic-Wide Association Studies (GWAS) and Heritability Studies(GWAS) and Heritability Studies

Slemenda et al 1992 Kelly et al 1993111 Male Twin Pairs

Compared MZ and DZ twins

BMD modestly higher MZ twins

Most of heritability eliminated once adjusted for non genetic factors

40 Twin pairs, predominantly female

Studied BMD changes femur and lumber spine in MZ and DZ twins

Estimated 60-80% heritability

Wide confidence interval and only lumber spine values significant

A lot of non genetic noiseA lot of non genetic noise(how much is non genetic?)(how much is non genetic?)

• BMIBMI• SmokingSmoking• AlcoholAlcohol• ActivityActivity• Chronic DiseaseChronic Disease• DrugsDrugs

Type 3 osteoporosisType 3 osteoporosis

• MalignancyMalignancy• CushingsCushings• Gastrointestinal disease, malabsorbtion and Gastrointestinal disease, malabsorbtion and

nutritionalnutritional• Chronic renal failureChronic renal failure• Inflammatory disease – especially RAInflammatory disease – especially RA• Endocrinopathies – hypertyroidism, hypogonadismEndocrinopathies – hypertyroidism, hypogonadism• Drugs Corticosteroids, chemotherapy, anti-Drugs Corticosteroids, chemotherapy, anti-

convulsants….convulsants….

Sounds a mess? Don’t Sounds a mess? Don’t Despair Despair

A way forwardA way forward

For Primary Osteoporosis – a simple solution

For Secondary Osteoporosis – a few illustrative exemplars

London Morphology DatabaseLondon Morphology Database>250 conditions associated with >250 conditions associated with

osteoporosisosteoporosis• Complex syndromes – eg Barakat Complex syndromes – eg Barakat

19961996

• Metabolic - aromatase deficiencyMetabolic - aromatase deficiency

• Mechanical – arthrogryphosis Mechanical – arthrogryphosis syndromessyndromes

Array-CGH methodArray-CGH method

TestGenomic

DNA

Reference Genomic

DNA

Rati

o

Position on Sequence

Cot-1 DNA

Genomic clones or

oligosspotted on glass slide

DNA gain

DNA loss

“Dye-flip” experiments commonly employed

Hadju-Cheney Syndrome and response Hadju-Cheney Syndrome and response to Bisphosphonatesto Bisphosphonates

Examples of Disorders in 2016Examples of Disorders in 2016• Stuve-WiedemannStuve-Wiedemann• Schimke Immuno-osseous dystrophySchimke Immuno-osseous dystrophy• Osteoporosis – pseudogliomaOsteoporosis – pseudoglioma• Kenny-CaffeyKenny-Caffey• TMEM38B OITMEM38B OI• OI/Bone fragilityOI/Bone fragility• Skeletal DysplasiasSkeletal Dysplasias• Hyperparathyroid disordersHyperparathyroid disorders

The effect of next generation The effect of next generation sequencingsequencing

Why has this happenedWhy has this happened The effect of NGSThe effect of NGS• MEN1MEN1• CDC73CDC73• CASRCASR• CDKN1ACDKN1A• CDKN1BCDKN1B• CDKN2BCDKN2B• RET (exons 8,10-RET (exons 8,10-

11,13-16)11,13-16)• AP2S1 (pArg15)AP2S1 (pArg15)

Large MEN1 pedigreeLarge MEN1 pedigree

Menin and CASR mutation studies Menin and CASR mutation studies normalnormal

2015 Oxford hyper- parathyroid panel

Confirmed CDC73 mutation

Why is it important to recognise Why is it important to recognise CDC73 hyperparathyroidism (HPRT2)? CDC73 hyperparathyroidism (HPRT2)?

• Non PenetranceNon Penetrance• Different spectrum of tumoursDifferent spectrum of tumours• Therefore not just managing HPTTherefore not just managing HPT• Parathyroid carcinomaParathyroid carcinoma• Jaw tumoursJaw tumours• Uterine tumoursUterine tumours• Renal tumoursRenal tumours

CDC73 can be variable and the CDC73 can be variable and the genetics doesn’t always give the genetics doesn’t always give the

answeranswer

Heterozygous c26delG(pArg9fs)

Biochemically and Genetically both Biochemically and Genetically both have hypophosphatasiahave hypophosphatasia

Very low AlkPhosVery low AlkPhosCompound heterozygous mutations TNALPCompound heterozygous mutations TNALPLong term Paediatric ITU and Asfotase alphaLong term Paediatric ITU and Asfotase alpha

Very low AlkPhosVery low AlkPhosHomozygous mutations TNALPHomozygous mutations TNALPAsymptomaticAsymptomatic

Patient seen in Joint Endocrine Patient seen in Joint Endocrine Genetic ClinicGenetic Clinic

OsteoporosisOn Bisphosponate

History Obtained in the History Obtained in the Endocrine Genetic ClinicEndocrine Genetic Clinic

OI and Osteoporosis On Bisphosponate

a few # as childAge 45

a few # as a childAge 41

History of #Childrens Hospital

History of #Childrens Hospital

Family Members at risk of OIFamily Members at risk of OI

271

140 127

442

0

50

100

150

200

250

300

DefinitelyAffected

StatusUncertain

at 50% risk PossiblyAffected

Obligatorycarriers

OI phenotypes and genotypesOI phenotypes and genotypesOI Type Inheritance Phenotype Gene Defect

Classical –Silence Type

IIIIIIIV

ADADADAD

MildLethalProgressiveModerate

Nul Col1A1Col7A1/Col1A2Col1A1/Col 1A2Col1A1/Col1A2

Other V

VI

AD

?AR

Distinctive histology/callusMineralisation defect

IFITM5

SERPINF1

3 hydroxylation defects

VII

VIIIIX

AR

ARAR

Hypomorphic (S)null (L)Severe to lethalModerate – severe

CRTAP

LEPRE1PP1B

Chaperone Defects

XXI

ARAR

Severe to lethalBRUCK progressive

SERPINH1FKBP10

Unclassified typesBruck Type II AR Contractures PLOD2Caffey Disease AD Cortical

hyperostosisCol1A1

Osteoblast maturation defect

AD Moderate SP7

The Reality – the answer to these The Reality – the answer to these questions was mostly NO!questions was mostly NO!

• Did we know where were they now?Did we know where were they now?• Did we know how many more children had been born?Did we know how many more children had been born?• Did we know the type / severity of their OI?Did we know the type / severity of their OI?• Did we need expensive genetic testing?Did we need expensive genetic testing?• Did we know if they were on any treatment?Did we know if they were on any treatment?• Was anybody monitoring adults? Was anybody monitoring adults?

• Did we need a very complex / expensive overhaul of Did we need a very complex / expensive overhaul of our pathways?our pathways?

Types of OsteoporosisTypes of OsteoporosisA very simple suggestionA very simple suggestion

Primary Secondary

Type 1

Type 2

Type 3

3 Simple actions3 Simple actions• Take a family historyTake a family history

• Assess if medical history in patient or relative is Assess if medical history in patient or relative is indicative of an underlying disorderindicative of an underlying disorder

• See if a joint clinic with a genetics colleague is See if a joint clinic with a genetics colleague is realisticrealistic

• But has genetics anything to really add?But has genetics anything to really add?

Audit of referrals to clinical genetics Audit of referrals to clinical genetics 20062006

GP27%

Genetics12%Obs &

Gynae15%

Paediatrics3%

Other34%

Endocrin-ology3%

Unknown6%

Figure 1. Referral source – OI Patients Referred to Genetics

Figure 2. Referral source – CAH Patients Referred to Genetics

GP17%

Obs & Gynae25%

Other13%

Paediatrics28%

Endocrin-ology1%

Ortho-paedics

8%

Unknown8%

GP27%

Genetics12%Obs &

Gynae15%

Paediatrics3%

Other34%

Endocrin-ology3%

Unknown6%

Figure 1. Referral source – OI Patients Referred to Genetics

Figure 2. Referral source – CAH Patients Referred to Genetics

GP17%

Obs & Gynae25%

Other13%

Paediatrics28%

Endocrin-ology1%

Ortho-paedics

8%

Unknown8%

Important Gene PathwaysImportant Gene Pathways

• Wnt / Beta CateninWnt / Beta Catenin

• RANKL/RANK/OPGRANKL/RANK/OPG

• Oestrogen and TestosteroneOestrogen and Testosterone

• PTH Calcium homeostasisPTH Calcium homeostasis

Fascinating science but just do not Fascinating science but just do not know how to apply clinically know how to apply clinically but :-but :-

• Wnt / Beta CateninWnt / Beta Catenin

• RANKL/RANK/OPGRANKL/RANK/OPG

• Oestrogen and TestosteroneOestrogen and Testosterone

• PTH Calcium homeostasisPTH Calcium homeostasis

Epigenetics and Future TherapyEpigenetics and Future Therapy

• Change of gene expression without changing the Change of gene expression without changing the coding sequencecoding sequence

• Three main mechanismsThree main mechanisms– Post transcriptional histone modificationPost transcriptional histone modification– MicroRNA’s (miRNA’s) in regulation of gene expressionMicroRNA’s (miRNA’s) in regulation of gene expression– DNA methylation in regulaion of gene expressionDNA methylation in regulaion of gene expression

Vrtanik, Marc and Ostanek 2014. Epigeneticc mechanisms in bone; Clin Chem Lab Medicine 52; 589-608

From Family History to EpigeneticsFrom Family History to Epigeneticsoror

A Holistic Approach made SimpleA Holistic Approach made Simple• Different clinical structures to match clinical serviceDifferent clinical structures to match clinical service

• A route to consider the unusual cases or rare A route to consider the unusual cases or rare disorders with secondary osteoporosisdisorders with secondary osteoporosis

• A mechanism to identify and follow up extended A mechanism to identify and follow up extended familyfamily

• Identifying cohorts for future researchIdentifying cohorts for future research

My Thanks to :-My Thanks to :-• Professor Neil GittoesProfessor Neil Gittoes

• Sue Stewart – Clinical nurse specialistSue Stewart – Clinical nurse specialist

• Lisa Cooper-Charles –W Mids Regional Genetics LaboratoryLisa Cooper-Charles –W Mids Regional Genetics Laboratory

• Authors of 2 excellent reviews – Authors of 2 excellent reviews – • Vrtacnik et al (2014) Epigenetics mechanisms in bone. Clin ChemLab Vrtacnik et al (2014) Epigenetics mechanisms in bone. Clin ChemLab

Med 52:589-608Med 52:589-608• Mitchell and Streeten (2013). Clinical impact of recent genetic Mitchell and Streeten (2013). Clinical impact of recent genetic

discoveries in osteoporosis. App of clinical genetics 6: 75-85 discoveries in osteoporosis. App of clinical genetics 6: 75-85