Alpha-sarcoglycanopathy presenting as myalgia and hyperCKemia in two adults with a long-term follow-up. Case reports.

Two patients with a paucisymptomatic hyperckemia underwent a skeletal muscle biopsy and massive gene panel to investigate mutations associated with inherited muscle disorders. In the SGCA gene, sequence analyses revealed a homozygous c.850C > T/p.Arg284Cys in patient 1 and two heterozygous variants (c.739G > A/p.Val247Met and c.850C > T/p.Arg284Cys) in patient 2. Combination of histology and immunofluorence studies showed minimal changes for muscular proteins including the α-sarcoglycan. These two cases highlight the advantages of next-generation sequencing in the differential diagnosis of mild myopathic conditions before considering the more invasive muscle biopsy in sarcoglycanopathies.

Milder forms of α-sarcoglicanopathies diagnosed in adulthood by NGS analysis.

INTRODUCTION: Sarcoglycanopathies (LGMD 2C2F) are a subgroup of limb-girdle muscular dystrophies (LGMD), caused by mutations in sarcoglycan genes. They usually have a childhood onset and rapidly progressive course with loss of ability to walk over 12-16 years. METHODS: Next generation sequencing (NGS) targeted gene panel was performed in three adult patients with progressive muscle weakness in which routine muscle histology and immunohistochemistry were not diagnostic. RESULTS: Genetic analysis revealed homozygous or compound heterozygous mutations in SGCA gene and Western Blot demonstrated protein reduction confirming the diagnosis of α-sarcoglicanopathy. DISCUSSION: Our cases evidence that the diagnosis of mild forms of alfa sarcoglicanopathy could be a challenge and suggest the possibility that they could be underdiagnosed. The use of Next generation Sequencing targeted gene panels is very helpful in the diagnosis of these patients.

Effects of Home Mechanical Ventilation on Left Ventricular Function in Sarcoglycanopathies (Limb Girdle Muscular Dystrophies).

Cardiac and respiratory function may be impaired in sarcoglycanopathies, a subgroup of muscular dystrophies due to sarcoglycan proteins (α, ß, γ, and δ) genes mutations. Management of patients with restrictive respiratory failure mainly relies on home mechanical ventilation (HMV). Little is known about the cardiac effects of prolonged mechanical ventilation in patients with muscular dystrophy and restrictive respiratory insufficiency. We aimed to assess the effects of HMV on cardiac function in sarcoglycanopathies. We retrospectively included 10 genetically proven patients with sarcoglycanopathy followed at the HMV unit of the Raymond Poincare University Hospital (4 patients with α-sarcoglycanopathy and 6 patients with γ-sarcoglycanopathy). We collected cardiorespiratory clinical baseline data and left ventricular ejection fraction (LVEF) at baseline before initiation of HMV and at the end of follow-up. At baseline, median age was 30.5 years (27 to 39) and median pulmonary vital capacity was 27% of the predicted value (21 to 36). Forty percent of the patients had documented sleep apnea. Cardiomyopathy, defined as LVEF <50%, was found in 3 patients with γ-sarcoglycanopathy. After a median follow-up of 3 years (1.0 to 4.5), there was a significant increase in LVEF after initiation of HMV, that is, 62% (48 to 65) versus 53% (45.5 to 56.5) (p = 0.0039). In conclusion, HMV in sarcoglycanopathies is not harmful and may protect left ventricular function by its thoracic physiological effects.

Alpha-sarcoglycanopathy presenting as exercise intolerance and rhabdomyolysis in two adults.

Two patients with exercise-induced myalgias and rhabdomyolysis with myoglobinuria were evaluated with muscle biopsy and comprehensive myopathy next generation sequencing (NGS) gene panels. Genetic analysis revealed homozygosity for two known pathogenic SGCA mutations (R284C in Patient 1 and V247M in Patient 2). Muscle biopsy showed minimal changes with normal immunohistochemistry for α-sarcoglycan. Western blotting showed 27% and 35% of normal α-sarcoglycan immunoreactivity when compared to age matched controls, confirming the diagnosis of α-sarcoglycanopathy in both patients. The sarcoglycan genes should be added to the differential diagnosis for cases that present with rhabdomyolysis, exercise intolerance, and hyperCKemia, even in the absence of muscle weakness or normal α-sarcoglycan immunohistochemistry. Work-up of patients with these types of non-specific presentation may be best facilitated through the use of non-specific NGS myopathy panels.

Be careful about abdominal discomfort in adult patients with muscular dystrophy.

Muscular dystrophies are genetic muscular disease with disability. Heart failure is a classical complication mainly in Duchenne muscular dystrophy (DMD). We report 2 cases of severe acute heart failure revealed by abdominal discomfort in a patient with DMD and in a patient with gamma-sarcoglycanopathy.

Cardiac involvement in Dutch patients with sarcoglycanopathy: a cross-sectional cohort and follow-up study.

INTRODUCTION: The aim of this study is to describe the frequency, nature, severity, and progression of cardiac abnormalities in a cohort of Dutch sarcoglycanopathy patients. METHODS: In this cross-sectional cohort study, patients were interviewed using a standardized questionnaire and assigned a functional score. Electrocardiography (ECG), echocardiography, and 24-h ECG were performed. RESULTS: Twenty-four patients with sarcoglycanopathy had a median age of 25 years (range, 8-59 years). Beta blockers were used by 13%, and 17% used angiotensin-converting enzyme inhibitors. ECG abnormalities were present in 5 (21%), and 4 (17%) fulfilled the criteria for dilated cardiomyopathy (DCM). There were no significant differences in median age or severity of disease between patients with or without DCM. Eleven patients were examined earlier. Median follow-up time was 10 years. Two of the 11 patients (18%) developed DCM during follow-up. CONCLUSIONS: Seventeen percent of the patients with sarcoglycanopathy were found to have dilated cardiomyopathy. We recommend biannual cardiac monitoring, including ECG and echocardiography.

Left ventricular function in alpha-sarcoglycanopathy and gamma-sarcoglycanopathy.

Sarcoglycanopathies are autosomic recessive muscular dystrophies, secondary to mutations of the sarcoglycan complex. Heart can be involved in sarcoglycanopathies. We sought to analyse left ventricular function in patients with alpha-sarcoglycanopathy and gamma-sarcoglycanopathy. We conducted a retrospective study that aimed to analyse clinical and echocardiographic data of patients with sarcoglycanopathies. Our study included 19 patients: eight patients with alpha-sarcoglycanopathy and 11 patients with gamma-sarcoglycanopathy. Mean age was 37.8 ± 8.7 years in alpha-sarcoglycanopathy and 36 ± 7.3 years in gamma-sarcoglycanopathy. Mean VC was, respectively, 36.3 ± 18 % in alpha-sarcoglycanopathy and 23.5 ± 6.8 % in gamma-sarcoglycanopathy (p 0.05). 1/8 patients disclosed a left ventricular dysfunction with a left ventricular ejection fraction (LVEF) <50 % in alpha-sarcoglycanopathy, whereas 5/11 patients disclosed a left ventricular dysfunction (LVEF < 50 %) in gamma-sarcoglycanopathy. LV was altered in gamma-sarcoglycanopathy than in alpha-sarcoglycanopathy (LVEF at 45.6 ± 18 vs. 59.6 ± 5.9 % p 0.018). We found a significant alteration of the left ventricular function in gamma-sarcoglycanopathy compared to alpha-sarcoglycanopathy.

[Heart involvement in sarcoglycanopathies]. / Cœur et sarcoglycanopathies.

Sarcoglycanopathies (SG) are autosomic recessive muscular dystrophies, secondary to mutations of the sarcoglycan complex. Clinical pictures include muscle weakness affecting mainly the proximal limb girdle musculature. We review heart involvement in this group of disease.