Session: Advances in genetics of cardiomyopathies

Clinical and functional consequences

associated to a PKP2 founder mutation in

north-west Spain

Presenter: Lorenzo Monserrat

Paris, 28 Aug 2011

A. Diez-Juan , MF. Ortiz, L. Perez-Alvarez, R. Barriales-Villa, DA. Garcia, J.

Moncayo-Arlandi, X. Fernandez, L. Nunez, L. Monserrat

Potential conflicts of interest

Lorenzo Monserrat:

Promoter and Stockholder:

Health in Code

•Primary and inherited affection of the myocardium(estimated

prevalence 1:5000 )

•Progressive replacement of right ventricular myocardium with

adipose and fibrous tissue (mainly RV, but also LV)

ARVC

DESMOSOMAL GENES

www.e-heart.org

•25 unrelated index cases with ARVC from A Coruña

(Galicia-Spain)

•Sequence analysis of 4 main desmosomal genes:

•Plakophilin-2 (PKP2)

•Desmoplakin (DSP)

•Desmoglein-2 (DSG2)

•Desmocollin-2 (DSC2)

COHORT

GEOGRAPHICAL DISTRIBUTION

•10 mutations (9 novel) in 17 of 25 pts 68%

•4 pts complex genotypes 16%

•1 homozygous

•1 compound heterozygous

•2 doble heterozygous

•3 mutations in more than 1 proband

•S329RfsX351 in PKP2 (9 cases)

•R375X in DSC2 (2 cases)

•C813R in DSG2 (2 cases)

GENETIC STUDIES

PROBAND PKP2 DSP DSC2 DSG2

1 S329RfsX351

2 S329RfsX351

3* S329RfsX351

E624D

4* S329RfsX351 K468Q

5 S329RfsX351

6* S329RfsX351 R375X

7 S329RfsX351

8 S329RfsX351

9 S329RfsX351

10* R375X (H)

11 IVS11+2T>C

12 M589T

13 IVS9-1G>C

14 R1945C

15 R907L

16 C813R

17 C813R

* Complex genotypes

18 carriers

8 non carriers

49 without

genetic study

9 families

S329RfsX351 – PKP2

8 ARVC

7 possible ARVC

3 not affected or healthy

1 possible ARVC

7 not affected or healthy

1 ARVC

1 possible ARVC

3 not affected or healthy,

44 without phenotypic study

Events in mutation carriers

2 Sudden deaths

4 Appropiate ICD shocks

1 Stroke related death

2 Strokes without death

Events in relatives without genetic study

3 Sudden deaths

2 Stroke related deaths

1 Stroke without death

EVENTS

SD

SD SD

aSD

aSD

ICDs

ICDs

ICDs

ICDs

HCM HCM

Stroke Stroke

x2

Stroke

Stroke

Stroke

Table - Genetic and clinical characteristics of S329RfsX351-PKP2 carriers

Table - Clinical characteristics of relatives without genetic diagnosis who had

adverse events

Fressart et al. Europace 2010;12:861-868

300

healthy

controls

?

PKP2 –

S329RfsX351

•Costa da Morte

(Death coast)

FOUNDER

EFFECT

PKP 2: Constructions

S329fsX351

(pb4086)

Armadillo domain Variable domain

N

´ C

´

hPKP2 V5

Esmeral V5 mPKP2

Esmeral V5 mPKP2

(Control)

Esmeral V5

Experimentals

S329fsX351

EXT

INT

INT

Plakophilin 2

S329fsX351

Control

H9C2

Rat ventricular cardiomyocytes

HL-1

Mouse atrial cardiomyocytes

Neonatal Cardiomyocytes

Rat ventricular cardiomyocytes

Esmeral V5

mPKP2

Esmeral V5 mPKP2

Esmeral V5

hPKP2 V5

S329fsX351

Esmeral V5 mPKP2

S329fsX351

Lentiviral vector

hPKP2

-v5

hPKP2

-v5 Control Control

Cytoplasmic Nuclear

v5

hPKP2

-v5

hPKP2

-v5 Control Control

Cytoplasmic Nuclear

PKP2

hPKP2 V5 mPKP2

Control Control hPKP2-v5 hPKP2-v5

HL-1

Mouse Atrial Cardiomiocytes

α- Tubulin α- Tubulin

Anti V5 Anti C-term

HL-1

Mouse Atrial Cardiomiocytes

Control hPKP2-v5 Control hPKP2-v5

γ-catenin Desmoplakin

Neonatal rat

ventricular

cardiomyocytes

Control hPKP2-v5

Anti-v5

Anti-PKP2

↑↑ PPAR-γ (Adipogenic factor)

↑ TGF-β2 and TGF β3 (Fibrosis factors)

↑ Vimentin (Adipogenic marker)

Fibrosis

factors

Adigogenic

marker

hPKP2 V5

CONCLUSIONS

•Mutations in 70% of ARVC cases

•S329RfsX351-PKP2 is a pathogenic mutation

associated with the development of ARVC

•Founder mutation in Galicia

•Incomplete penetrance in young carriers

•Severe expression in cases with additional

pathogenic mutations

•Arrhythmic sudden death and strokes

•LV involvement relatively common

CONCLUSIONS

•Functional studies:

•PKP2 not only a structural protein

•Nuclear localization of mutant PKP2 could

be responsible of anomalous cardiomyocyte

gene expression

•Support for a role for immunofluorescence

studies in the diagnosis of ARVC (Asimaki et al)