Cardiopulmonary involvement is manifested by increased respiratory rate, use of accessory muscles for respiration, recurrent chest infections, decreased air entry in the left lower zone (due to cardiomegaly), arrhythmias, and evidence of heart failure.Before developing a treatment, median age at death in untreated cases was 8.7 months, usually due to cardiorespiratory failure; However, this outcome is drastically changed since treatment has been available, improving with early access to treatment. Late onset form
This form differs from the infantile principally in the relative lack of cardiac involvement. The onset is more insidious and has a slower progression. Cardiac involvement may occur but is milder than in the infantile form. Skeletal involvement is more prominent with a predilection for the lower limbs.Late onset features include impaired cough, recurrent chest infections, hypotonia, progressive muscle weakness, delayed motor milestones, difficulty swallowing or chewing and reduced vital capacity. Prognosis depends on the age of onset of symptoms with a better prognosis being associated with later onset disease. Cause
It has an autosomal recessive inheritance pattern. This means the defective gene is located on an autosome, and two faulty copies of the gene — one from each parent — are required to be born with the disorder.
On June 14, 2007, the Canadian Common Drug Review issued their recommendations regarding public funding for Myozyme therapy. Their recommendation was to provide funding to treat a tiny subset of Pompe patients (Infants less one year of age with cardiomyopathy).On May 26, 2010, FDA approved Lumizyme, a similar version of Myozyme, for the treatment of late-onset Pompe disease. Lumizyme and Myozyme have the same generic ingredient (alglucosidase alfa) and manufacturer (Genzyme Corporation). The difference between these two products is in the manufacturing process. Myozyme is made using a 160-L bioreactor, while Lumizyme uses a 4000-L bioreactor. Because of the difference in the manufacturing process, the FDA claims that the two products are biologically different. Moreover, Lumizyme is FDA approved as replacement therapy for late-onset (noninfantile) Pompe disease without evidence of cardiac hypertrophy in people 8 years and older. Myozyme is FDA approved for replacement therapy for infantile-onset Pompe disease.In July 2021, the European Medicines Agency (EMA) recommended the authorization of avalglucosidase alfa. Avalglucosidase alfa (Nexviazyme) was approved for medical use in the United States in August 2021. Prognosis
The prognosis for individuals with Pompe disease varies according to the onset and severity of symptoms, along with lifestyle factors.