Revista Portuguesa de Pneumologia Revista Portuguesa de Pneumologia
Rev Port Pneumol 2017;23:208-15 - Vol. 23 Num.4 DOI: 10.1016/j.rppnen.2017.02.004
Original article
Prevalence of late-onset pompe disease in Portuguese patients with diaphragmatic paralysis – DIPPER study
M.J. Guimarãesa,, , J.C. Winckb, B. Condec, A. Mineirod, M. Raposoe, J. Moitaf, A. Marinhog, J.M. Silvah, N. Piresi, S. Andréj, C. Loureirof
a Hospital Guimarães, Centro Hospitalar do Alto Ave, Guimarães, Portugal
b Universidade do Porto, Porto, Portugal
c Centro Hospitalar de Trás-os-Montes e Alto Douro, Vila Real, Portugal
d Hospital de Santa Marta, Centro Hospitalar de Lisboa Central, Lisboa, Portugal
e Hospital Egas Moniz, Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal
f Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
g Centro Hospitalar de São João, Porto, Portugal
h Hospital Sousa Martins, Unidade Local de Saúde da Guarda, Guarda, Portugal
i Hospital de Santa Maria Maior, Barcelos, Portugal
j Centro Hospitalar do Porto, Porto, Portugal
Received 26 July 2016, Accepted 15 February 2017
Abstract

Pompe disease is a rare autosomal recessive neuromuscular disorder caused by acid α-glucosidase enzyme (GAA) deficiency and divided into two distinct variants, infantile- and late-onset. The late-onset variant is characterized by a spectrum of phenotypic variation that may range from asymptomatic, to reduced muscle strength and/or diaphragmatic paralysis. Since muscle strength loss is characteristic of several different conditions, which may also cause diaphragmatic paralysis, a protocol was created to search for the diagnosis of Pompe disease and exclude other possible causes.

Methods

We collected a sample size of 18 patients (10 females, 8 males) with a median age of 60 years and diagnosis of diaphragmatic paralysis of unknown etiology, followed in the Pulmonology outpatient consultation of 9 centers in Portugal, over a 24-month study period. We evaluated data from patient's clinical and demographic characteristics as well as complementary diagnostic tests including blood tests, imaging, neurophysiologic and respiratory function evaluation. All patients were evaluated for GAA activity with DBS (dried blood test) or serum quantification and positive results confirmed by serum quantification and sequencing.

Results

Three patients were diagnosed with Pompe's disease and recommended for enzyme replacement therapy. The prevalence of Pompe, a rare disease, in our diaphragmatic paralysis patient sample was 16.8%.

Conclusion

We conclude that DBS test for GAA activity should be recommended for all patients with diaphragmatic paralysis which, despite looking at all the most common causes, remains of unknown etiology; this would improve both the timing and accuracy of diagnosis for Pompe disease in this patient population. Accurate diagnosis will lead to improved care for this rare, progressively debilitating but treatable neuromuscular disease.

Keywords
Diaphragmatic, Paralysis, Pompe
Rev Port Pneumol 2017;23:208-15 - Vol. 23 Num.4 DOI: 10.1016/j.rppnen.2017.02.004