Investigating the family after a sudden cardiac death. Dr Catherine Mercer Consultant Clinical Geneticist, Wessex

Transcription

1 Investigating the family after a sudden cardiac death Dr Catherine Mercer Consultant Clinical Geneticist, Wessex

2 Sudden adult deaths subdivided Sudden Adult Death Sudden Cardiac Death Sudden Arrhythmic Death

3 What is SADS? 0-40 years Sudden Adult Death Sudden Cardiac Death Sudden Arrhythmic Death

4 Sudden Cardiac Death (0-40 years) Myocarditis Cause identified (60%) Coronary Artery Disease Congenital Heart Disease HCM ARVC DCM Aortopathy Cardiomyopathies

5 Sudden Cardiac Death (0-40 years) Myocarditis Cause identified (60%) Coronary Artery Disease Congenital Heart Disease HCM ARVC DCM Aortopathy Genetic cause common, typically autosomal dominant

6 Sudden Cardiac Death (0-40 years) No cause identified 40% Causes include: LQTS Brugada CPVT Genetic cause common, typically autosomal dominant

7 Sudden deaths that need investigation Sudden Adult Death Sudden Cardiac Death Sudden Arrhythmic Death

8 Autosomal dominant disease: First Degree Relatives at risk Sudden Adult Death Sudden Cardiac Death Sudden Arrhythmic Death

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10 Review of hospital notes of affected brother: Previously generally fit and well Varicose vein surgery 10 years prior Laparoscopic cholecystectomy Finance manager Married Wife 32 weeks pregnant

11 Sudden onset chest pain, radiating to jaw and back Continuous Aggravated by movement Seen in A & E, CT scan next morning Aortic root aneurysm, 7cm diameter Type A aortic dissection, extensive

12 Marfan Syndrome

13 Genetic testing in deceased brother: Mutation report: c.5999g>c, p.cys2000ser in Fibrillin 1

14 Mutation report: Heterozygous for a G to

15 Mutation report: Heterozygous for a G to

16 Mutation report: Heterozygous for a G to

17 Mutation Died suddenly report: following a Heterozygous bicycle ride, for aged a G 34 to years, HCM known, no genetic testing

18 Died in 30s Died in 50s, HCM reported by family Mutation Died suddenly report: following a Heterozygous bicycle ride, for aged a G 34 to years, HCM known, no genetic testing

19 Hospital notes review: Numerous letters from 1980s confirming diagnosis of HCM Died in 30s Died in 50s, HCM reported by family Mutation Died suddenly report: following a Heterozygous bicycle ride, for aged a G 34 to years, HCM known, no genetic testing

20 Died in 30s Died in 80s, HCM reported by family Mutation DNA extracted report: post Heterozygous mortem, testing for a underway G to

21 Issue date: August 2008 Identification and management of familial hypercholesterolaemia

22 Died following out of hospital VF arrest, age 40, known history of hypertension, raised BMI Mutation report: Heterozygous for a G to

23 Review of medical notes from affected mother: No prior history of cardiac disease Cardiac arrest at home, resuscitated, cardioverted, LBBB Angiogram: NAD CT head: NAD Clinical diagnosis: cardiac arrest, hypoxic brain injury

24 Review of post mortem: This is sudden cardiac death due to left ventricular hypertrophy with myocyte hypertrophy and fibrosis in keeping with hypertensive disease Normal cardiomyocyte histology Cardiomyocyte disarray

25 Died following out of hospital VF arrest, age 40, known history of hypertension, raised BMI Mutation No genetic report: testing indicated Heterozygous for a G to

26 Dilated Idiopathic Cardiomyopathy Genetic Drugs/ Toxins Infection Immune

27 Died from heart failure, known DCM, age 37 years

28 Died from heart failure, known DCM, age 37 years

29 Sudden Cardiac Death cause identified Targeted history and clinical investigations Genetic testing if DNA available Screening begins with First Degree Relatives (FDRs) of deceased

30 SCD vs SADS Sudden Cardiac Death Sudden Arrhythmic Death SADS: negative postmortem

31 The negative PM No other cause of death identified Structurally normal heart No abnormal histopathological findings in the heart Normal blood toxicology screen No pre-death clinical features to suggest other causes of sudden death Cause of death may be genetic

32 Sudden Arrhythmic Death (0-40 No cause identified 40% years) LQTS Brugada CPVT

33 Long QT Syndrome HCM DCM

34 Long QT Syndrome HCM DCM

35 Brugada Syndrome ST segment abnormalities in leads V1-V3 Diagnosis difficult: may need Ajmaline challenge HCM Risk of ventricular arrhythmias Typical presentation is in adulthood DCM

36 Brugada Syndrome ST segment abnormalities in leads V1-V3 Diagnosis difficult: may need Ajmaline challenge HCM Risk of ventricular arrhythmias Typical presentation is in adulthood DCM Philippines: Bangungut scream followed by death during sleep Thailand: Lai Tai death during sleep Japan: Pokuri unexpected death during sleep

37 Catecholamineragic Polymorphic Ventricular Tachycardia Episodic syncope due to fast VT HCM May degenerate into ventricular fibrillation Typical presentation is in childhood Around 30% present with sudden death DCM Diagnosis: typically via exercise test

38 Died while swimming, age 31 years. Negative post mortem. No DNA available.

39 Investigations of relatives ECG Echo HCM Exercise test Holter monitor DCM Cardiac MR Ajmaline challenge

40 Investigations of relatives

41 Died while swimming, age 31 years. Negative post mortem. DNA available.

42 Molecular autopsy HCM DCM Semsarian et al.

43 Mutation identified; cascade test in family members.

44 The role of genetic testing in Sudden Adult Death May identify pathogenic mutation: - gives certainty about diagnosis - allows cascade screening of relatives Blind testing not useful in relatives

45 Why isn t genetic testing the magic bullet in SADS cases?

46 Why isn t genetic testing the magic bullet in SADS cases?

47 Comparing 3,000,000,000 base pairs compared to the standard 3,000,000,000 base pairs. 6,400,000 differences 700,000 will be rare 3000 would affect a protein Is the variant shared by other affected family members? Has the gene/variant been linked to similar symptoms

48 Assessment of the family in cases of young sudden death Family history Explore hospital records from affected individual, including post mortem Establish if DNA has been stored or not Screen first degree relatives; targeted where possible, ideally in specialist clinic Discuss genetic testing with the family if DNA available

49 The role of the GP Take family history Encourage DNA storage Baseline screen (symptoms, ECG) Refer to Cardiology and Clinical Genetics (Explore hospital records from affected individual, including post mortem)

50 Idiopathic Arrhythmogenic Right Ventricular Cardiomyopathy

51 The role of the GP Take family history Encourage DNA storage Baseline screen (symptoms, ECG) Refer to Cardiology and Clinical Genetics (Explore hospital records from affected individual, including post mortem)