Résumé :
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Background :Alpha sarcoglycanopathy ( LGMD 2D) and gamma Sarcoglycanopathy (LGMD 2C) are autosomic recessive muscle diseases (myopathies), secondary to mutations of the sarcoglycan complex. This complex consists of four transmembrane proteins(alpha-, beta-, gamma-, delta- sarcoglycan) and contributes to the stability of the plasma membrane cytoskeleton. Depending on which protein is abnormal, four sarcoglycans (SG ) are described referred as alpha-, beta-, gamma-, delta -SG. Each sarcoglycan is expressed both in skeletal and cardiac muscle. Muscular disorder in SG is similar in the four types resulting in proximal muscle weakness (referred as Limb Girdle Muscular Dystrophy: LGMD). The link between SG subtype and heart disease is not well known. We conducted a review of LGMD type 2C and LGMD type 2D followed in our unit to assess heart involvement in adult patients with SG and to describe the link between heart involvement and molecular profile.Material and methods: Adults patients with genetically proven SG, referred in our unit for the follow up of mechanical ventilation whether it is invasive or non invasive (n=27). Left ventricular ejection fraction was measured using Simpson or Teicholtz method in 23 patients, 4 patients had only visual evaluation. Patients with LVEF <50 % or rated as low were considered to have systolic heart failure (SHF).Results : Ten patients had alpha-SG (LGMD 2D) and 17 gamma-SG (LGMD 2C) (Table). All subjects where disabled and confined to wheeling chair. Respiratory failure was constant with restrictive syndrome. Overall prevalence of systolic heart failure was high (30 %). Mean EF was lower in patients with gamma-SG (53 %) than in patients with gamma-SG (67 %) (p=0.01). No patients with alpha-SG had SHF whereas 47 % of patients with gamma-SG had SHF (p<0.01).Conclusion : We found a high prevalence of SHF in patients with SG and a strong association between the type of SG and a low LVEF. Only patients affected with gamma-SG had SHF. THISISATABLE< cellspacing="1" cellpadding="0" border="0" style=""> LGMD 2D (n=10) LGMD 2C (n=17) Overall (n=27) Age, years 37 (9) 32 (7) 34 (8) Body mass index, kg/m2 17 (4) 19 (5) 18 (4.5) LVED diameter index, mm/m2 25.5 (3) 27 (4.5) 26 (4) LVEF, % 67 (7) 53 (17) 58 (15) SHF, n (%) 0 (0) 8 (47) 8 (30)
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