Prospective evaluation of the familial prevalence of the brugada syndrome.
The familial prevalence of Brugada syndrome (BrS) in a consecutive series of patients was prospectively determined. BrS is genetically determined with autosomal dominant transmission. The familial prevalence of the BrS is unknown. A detailed pedigree of each family of patients with BrS was assembled and permission was obtained to invite relatives for electrocardiography and an ajmaline challenge. Sixty-two of 98 patients participated in the study and were included over a 6-year period. SCN5A genotyping was performed in 56 of these 62 patients (90%). Electrocardiograms (ECGs) of 488 relatives (mean age 38 ± 20 years, 45% men) were recorded and 270 of these relatives agreed to undergo an ajmaline challenge. Spontaneous type 1 BrS ECG was found in 4 of 488 relatives (0.8%). In the group of relatives in whom ajmaline challenge was performed (n = 270), the finding was positive in 79 subjects (29%). SCN5A genotyping identified 5 other affected relatives. As a result, the total number of affected relatives was 88. Standard 12-lead ECG was normal in 64 of the 88 affected relatives (73%). Mean percentage of affected relatives per family was 27 ± 32% (95% confidence interval 19 to 35). Familial forms of BrS were observed in 41 of the 62 families (66%) and no SCN5A mutations were found in sporadic forms. In conclusion, after active family screening affected relatives were found in almost 1/3 of subjects. BrS appeared to be a familial disease in 2/3 of subjects.
Centre d'Activité de Rythmologie, Hôpital Sud, Centre Hospitalier Universitaire d'Amiens-Picardie, France. hermida.jean-sylvain@chu-amiens.fr
Jean-Sylvain
JS
Hermida
Elise
E
Dassonvalle
Isabelle
I
Six
Carole
C
Amant
François
F
Coviaux
Jérôme
J
Clerc
Didier
D
Herent
Alexis
A
Hermida
Jacques
J
Rochette
Geneviève
G
Jarry
D000328:Adult; D053840:Brugada Syndrome / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D004247:DNA / Q000235:genetics*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000235:genetics*; D009154:Mutation; D062554:NAV1.5 Voltage-Gated Sodium Channel; D010375:Pedigree; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D015222:Sodium Channels / Q000235:genetics*
D009124:Muscle Proteins; D062554:NAV1.5 Voltage-Gated Sodium Channel; C568320:SCN5A protein, human; D015222:Sodium Channels; D004247:DNA