[Autosomal dominant limb-girdle muscular dystrophy associated with conduction defects (LGMD1B): a description of 8 new families with the LMNA gene mutations].
BACKGROUND
Limb girdle muscular dystrophy type 1b (LGMD1B), due to LMNA gene mutations, is a relatively rare form of LGMD characterized by proximal muscle involvement associated with heart involvement comprising atrio-ventricular conduction blocks and dilated cardiomyopathy. Its clinical and genetic diagnosis is crucial for cardiac management and genetic counselling. Seven LMNA mutations have been previously reported to be responsible for LGMD1B.


METHODS
We describe the neurological and cardiologic features of 14 patients belonging to 8 families in whom we identified 6 different LMNA mutations, 4 of them having never been reported. Results. Eleven patients had an LGMD1B phenotype with scapulohumeral and pelvic-femoral involvement. Thirteen patients had cardiac disease associating conduction defects (12 patients) or arrhythmias (9 patients). Seven patients needed cardiac device (pacemaker or implantable cardiac defibrillator) and two had heart transplantation.


CONCLUSIONS
This study allowed us to specify the clinical characteristics of this entity and to outline the first phenotype/genotype relations resulting from these observations.
Ben Yaou
R
R
INSERM U582-Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris. r.benyaou@myologie.chups.jussieu.fr
Bécane
H-M
HM
Demay
L
L
Laforet
P
P
Hannequin
D
D
Bohu
P-A
PA
Drouin-Garraud
V
V
Ferrer
X
X
Mussini
J-M
JM
Ollagnon
E
E
Petiot
P
P
Penisson-Besnier
I
I
Streichenberger
N
N
Toutain
A
A
Richard
P
P
Eymard
B
B
Bonne
G
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000503:physiopathology; D015415:Biomarkers; D003402:Creatine Kinase / Q000097:blood; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006331:Heart Diseases / Q000000981:diagnostic imaging / Q000209:etiology / Q000235:genetics; D006801:Humans; D034904:Lamin Type A; D034882:Lamins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000473:pathology; D049288:Muscular Dystrophies, Limb-Girdle / Q000150:complications / Q000235:genetics* / Q000503:physiopathology*; D009154:Mutation / Q000235:genetics / Q000502:physiology; D009431:Neural Conduction / Q000502:physiology*; D010375:Pedigree; D010641:Phenotype; D014057:Tomography, X-Ray Computed
D015415:Biomarkers; C494847:LMNA protein, human; D034904:Lamin Type A; D034882:Lamins; D003402:Creatine Kinase