Sian Ellard

1. Genetic aetiology defines optimal treatment in monogenic diabetes Sian Ellard Consultant Molecular Geneticist and Professor of HumanMolecular Genetics

2. “The best blood test I ever had” “From 7th December 2001 after 27 years of insulin injections I began to take tablets for the diabetes instead. For more than 3 years now my diabetes has been controlled satisfactorily with tablets rather than insulin. The benefits to me have been quite profound – it’s so much easier to take tablets each day rather than having to inject with all the inconvenience and discomfort”

3. Treating diabetes METFORMIN Type 2 INSULIN Type 1 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 Age of diagnosis (years)

4. Aetiology of diabetes Type 2 Neonatal Type 1 MODY MIDD 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 Age of diagnosis (years)

5. Maturity-onset diabetes of the young (MODY) • Young onset, non-insulin dependent diabetes • Beta cell dysfunction • Autosomal dominant inheritance • Accounts for 1-2% diabetes • Genetic heterogeneity Tattersall (QJM 1974)

6. Insulin secretion in the pancreatic beta-cell Ca2+ Voltage dependent Ca2+ channel Depolarisation Glucose GLUT2 glucose transporter

7. GCK mutations cause a spectrum of diabetes/hyperinsulinism phenotypes Hyperinsulinism Mild fasting hyperglycaemia PNDM Clinical severity Clinical severity Heterozygous Heterozygous Homozygous Activating Inactivating

8. GCK-MODY: Mild fasting hyperglycaemia GCK 20 16 12 Fasting blood Glucose 8 Normal (mmol/l) 4 0 0 20 40 60 80 100 Age (yr) Pearson et al 2001 Diabetes

9. Liam • Mother: Gestational diabetes on screening. Post pregnancy FPG 7.6 mmol/l, 2hr 8.8 mmol/l. Diet treated. • Liam: Diagnosed age 6. Insulin treated (0.3U/kg) with excellent control. Heterozygous GCK mutation identified and insulin stopped. Latest HbA1c 6.1%. • Insulin injections stopped for children misdiagnosed with type 1 diabetes (n=8)

10. HbA1c does not change on treatment in patients with GCK mutations (n=32) HbA1c%

11. Treatment of diabetes METFORMIN INSULIN Type 2 Type 1 DIET GCK MODY 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 Age of diagnosis (years)

12. HNF1A-MODY: Progressive form of diabetes Transcription factor (HNF1A/4A) 20 16 12 Fasting blood Glucose GCK 8 (mmol/l) Normal 4 0 0 20 40 60 80 100 Age (yr) Pearson et al 2001 Diabetes

13. OGTT: GCK vs HNF1A-MODY HNF1A *** *** GCK European MODY Consortium (n=364) Stride et al 2002 Diabetologia

14. Dan • Four generation history of diabetes affecting 14 family members. • Diabetes diagnosed at 16 years, GAD antibody negative. Insulin treated (HbA1c 6.8%). Problems with severe hypos. • HNF1A mutation identified 8 months later, now treated with gliclazide (HbA1c 5.7%).

15. Sensitivity to sulphonylureas in patients with HNF1A mutations 1 Gliclazide Metformin 0 1 2 -1 -2 Change in FPG mmol/l -3 Type 2 -4 HNF1A MODY Error Bars represent 95% -5 confidence intervals -6 p<0.0001 -7 Pearson et al 2003 Lancet

16. Insulin secretion in the pancreatic beta-cell Ca2+ Voltage dependent Ca2+ channel Depolarisation Glucose GLUT2 glucose transporter X X X

17. HNF1A-MODY: Treatment after genetic diagnosis 43 patients with HNF1A diabetes on insulin from diagnosis to genetic test Median duration of diabetes = 18 years 35 transferred to oral agents 8 remain on insulinTransfer not attempted Median duration of diabetes = 8 years 25 remain off insulin 10 back on insulin 4 SU + Ins 6 Ins only 16 HBA1c < 7.5% 4 HbA1c > 7.5% but improved by >1% 4 HbA1c > 7.5% but unchanged 1 HbA1c > 7.5% deteriorated 3 HbA1c < 7.5% 1 HbA1c > 7.5% 2 HbA1c < 7.5% 4 HbA1c > 7.5% 80% had improved control Shepherd et al 2009 Diabetic Medicine

18. Coming off insulin • At least 57 UK patientshave transferred to sulphonylureas • ‘Even though I take these tablets I don’t feel like a diabetic anymore .. I feel a lot freer’ Shepherd et al 2004 Clinical Medicine

19. Treatment of diabetes METFORMIN INSULIN Type 2 LOW DOSE SULPHONYLUREA Type 1 HNF1A MODY DIET GCK MODY 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 Age of diagnosis (years)

20. A clinical classification of neonatal diabetes: the pre-genetic era Neonatal diabetes 45%Transient(TNDM) 45%Permanent(PNDM) 10%Syndromes& Pancreaticaplasia

21. Definition of Neonatal Diabetes • Pre-genetic: <1 or <1.5 or <3 months • Post-genetic: <6 months HLA analysis suggests Type 1 diabetes very uncommon before 6 months (n=189) % High Risk T1D HLA Iafusco et al Diabetologia 2002,Edghill et al Diabetes 2006

22. A molecular genetic classification of neonatal diabetes: the post genetic era Neonatal diabetes (< 6 months) 45%Transient(TNDM) 45%Permanent(PNDM) 10%Syndromes& Pancreaticaplasia 29% 3% 71% 45% 16% 12% 15% 11% 6q24 INS NEUROD1 PTF1AFOXP3 HNF1B EIF2AK3IPF1 GLIS3 KCNJ11 (Kir6.2) ABCC8 (SUR1) GCK

23. Insulin secretion in the pancreatic beta-cell Ca2+ Voltage dependent Ca2+ channel Depolarisation Glucose GLUT2 glucose transporter

24. ATP  Mutations in 10/29 patients dx < 6 months wild type R201Hmutation Gloyn et al NEJM 2004

25. Kir6.2 genotype/phenotype relationship 68% 5% 11% 16% PermanentNeonatalDiabetes alone TransientNeonatalDiabetes IntermediateDEND DEND syndrome Clinical severity R50P G53S R50Q Q52R V59G C166Y C166F I296V L164P R201H R201C Y330C Y330S G53R V59M I182V R201H E227K E229K

26. Modulate electrical activity and transmitter release at brain synapses. Protect against seizures Mediate the uptake of glucose in skeletal muscle cells Why do Kir6.2 mutations cause extra-pancreatic features? KATP CHANNEL FUNCTION Insulin secretion in the pancreas

27. Neurological features DEND syndrome Intermediate DEND (V59M) Developmental delay (severe) Epilepsy (<12 months) Neonatal Diabetes Developmental delay (mild) No epilepsy Neonatal Diabetes Hattersley& Ashcroft Diabetes 05 Gloyn et al NEJM 04 Gloyn et al EJHG 06

28. Severity of ATP insensitivity not position of the mutation defines phenotype K+ Outside Selectivity filter + + V59G Q52 + + Membrane V59G, V59M Q52R, G53D Slide Helix S3C, R4C H46Y, R50Q, R50P K170T, K170N, E179A, I182V R201H, R201C, R201L L233F, E227K, E229KG334D ATP + Inside I296L Proks 2004, Gloyn 2004,Shimora 2006, Masia 2007, Flanagan, Ellard, Hattersley unpublished

29. Kir6.2 genotype/phenotype relationship 68% 5% 11% 16% PermanentNeonatalDiabetes alone TransientNeonatalDiabetes IntermediateDEND DEND syndrome Clinical severity R50P G53S R50Q Q52R V59G C166Y C166F I296V L164P R201H R201C Y330C Y330S G53R V59M I182V R201H E227K E229K functional severity

30. SUR1 mutations also cause neonatal diabetes

31. SUR1 genotype/phenotype relationship F577L D1039N L438F L451P H1024Y V324M outside M1290V V86A/G membrane R1314H inside P45L E1327K E382K N72S R1183W/Q A1185E R1380C/H/L F132L/V L135P R306H G1401R L225P T229I I1425V P206L P207S E208K D209E/N Q211K D212I/N V1523A/L R826W G832D Y263D G296R E1507G A1510T NBD1 NBD2 TNDM PNDM

32. SUR1 mutations in PNDM Permanent Neonatal Diabetes Mellitus with no KCNJ11 mutation (n=59) Heterozygous de novo ABCC8 mutation (n=9) DOMINANT Compound heterozygous, homozygous or mosaic ABCC8 mutation (n=8) RECESSIVE N/N N/N L438F/N M1290V/N Compound heterozygous (n=5) Q211K/N L438F/M1290V Ellard et al AJHG 2007

33. MembraneHyperpolarised Membranedepolarised No calcium influx Calcium influx No insulin secretion Insulin secretion The mutated KATP channel could close with sulphonylureas Glucose Sulphonylurea Sulphonylureas closeKATP channel ATP does not close KATP channel  ATP

34. Patients with Kir6.2 mutations can be treated with sulphonylureas Tolbutamide since diagnosis 3/12 Now 46yrFPG 6.2 mmol/lC peptide 613 pmol/l Insulin Treated Insulin Treated

35. Sulphonylurea therapy successful for 44/49 patients with Kir6.2 mutations 8.1% 6.4% Pearson et al 2006 NEJM

36. Glucose values fluctuate lessas well as being lower Insulin pump 7.5 mg Glibenclamide Zung et al JCEM 04

37. Patients with SUR1 mutations also respond to sulphonlyureas 14 12 10 p=0.022 8 6 Glycated Haemoglobin (%) 4 On insulin On sulphonylurea Rafiq et al 2008 Diabetes Care

38. Sulphonylurea transfer successful for 91% of patients with a KATP channel mutation 237 insulin-treated patients with a KATP channel mutation 111 Successfully transferred from insulin to SU 115 Transfer not attempted, in progress, or no information 11 Transfer not successful

39. Response in vitro of mutated Kir6.2 to tolbutamide predicts response to SU treatment Some failed to transfer All transferred 100 Failed to transfer 90 80 70 60 Tolbutamide Block (%) 50 40 30 20 10 0 WT R201H H46Y I296L G53R G53N R50Q Q52R L164P R201L R201C

40. Most patients with DEND syndrome do not respond to sulphonylurea treatment Shimomura et al Neurology 2007 • Most severe mutations - usually least responsive to SUs • 5/6 : no clinically significant response either for diabetes or neurological symptoms (Masia et al Diabetes 2007, Sumnik et al Diabetic Medicine 2007) • One patient (Kir6.2 I167L) stopped insulin (2.3mg/kg/day glibenclamide) and no further seizures

41. Impact on family life “….Before the diagnosis of Jack’s disorder we were unable to live the life of a normal family. Since starting his treatment family life has completely changed. He’s gone from a child who was either completely manic because his sugars were through the roof or lethargic and grumpy because he was having a hypo, to a normal child. (Jack’s mum)

42. Easier to take tablets • Diagnosed at 15 weeks • Heterozygous for V59M • Learning difficulties • Transferred at 18 years

43. Similar impact around the world ‘After 10 yrs of insulin the only dream Marquis had was to be able to stay overnight at his best friends’, which was not even a consideration while on insulin. Now he will be going to slumber parties !’ Tennessee ‘This summer for the first time Peter played football with his local team and attended ‘camp’ by himself. He is very happy, joyful and calm. We feel as if we have witnessed a miracle, we cannot even describe this happiness. After 12 years we saw sunshine again.’ Poland

44. Changing treatment might improve neurological features • Glibenclamide binds to muscle KATP (SUR2A) and peripheral nerves KATP(SUR1) • SUs may cross the Blood Brain Barrier, could bind to cerebral KATP (SUR1) Slingerland et al Diabetologia (2006) “Within 1 month of starting glibenclamide there was a marked improvement in motor function resulting in the patient progressing from being unable to stand unaided to walking independently”

45. Improved motor function • Intermediate DEND syndrome (V59M) • Developmental delay. Motor skills assessed as 9 months aged 2 years.

46. Improved concentration and speech Jack Improved concentration “The school was amazed at the change in his ability to concentrate” Improved speech “He came out of school in July (2006) and said “Hellomummy” for the first time”.

47. Prognosis for patients with Kir6.2 V59M? • Severe developmental delay; lives in care institution (transfer at 60 years) • Mild developmental delay; works as a teaching assistant (18 years) • Improved speech and concentration (4 years) • Improved motor function (2 years) • Prognosis if treated with SUs from diagnosis?

48. Carsyn • Born in December 2006 • Diagnosed with diabetes at 6 weeks • V59M mutation identified aged 8 weeks • Transfer from insulin to glibenclamide completed by 9 weeks • Normal developmental milestones aged 2 years

49. Treatment of diabetes HIGH DOSE SULPHONYLUREA METFORMIN INSULIN Type 2 KATP Neonatal diabetes Type 1 LOW DOSE SULPHONYLUREA HNF1A MODY DIET GCK MODY 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 Age of diagnosis (years)