Ethnicity may affect the accuracy of screening tools for Pompe disease (PD), according to a study recently published in Frontiers in Neurology.
“A modified high-risk screening strategy should be proposed to establish an early diagnosis in Chinese patients with [late-onset PD],” the authors wrote.
This prospective study included 492 participants from 20 different medical centers in China. Their mean age was 42 years. All individuals had either persistently increased creatinine kinase not explained by other medical conditions, axial/limb-girdle muscular weakness, or respiratory insufficiency that was not attributable to another etiology.
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A total of 26 participants (5.3%) tested positive in a dried blood spot. Nonetheless, only 8 cases (1.6%) could confirm a diagnosis of PD through molecular studies. Also, a tandem mass spectrometry assay identified the differing GAA activity between patients with PD and those with pseudodeficiencies.
Importantly, the diagnosis of late-onset PD was delayed 5 years on average from the onset of symptoms among this sample. All participants diagnosed with PD had respiratory insufficiency with a decreased forced vital capacity, at a mean of 48%. All of them also showcased axial/proximal muscle weakness as well.
On the other hand, creatine kinase values did not seem to associate as much with the presence of PD. Values ranged from normal to an increase of over 5-fold the upper limit among individuals with this disease. No participant with a positive diagnosis had isolated high creatinine kinase plasma levels.
Upon diagnosis, 3 patients initiated enzyme replacement therapy. At the 1-year follow-up, all had improved scores on the 6-minute walking test and manual muscle test. Respiratory parameters, however, only mildly improved in 1 patient.
“Regarding the limited efficiency of treatment in respiratory parameters, the early diagnosis is even more important in adult Chinese [late-onset PD], given the preferential respiratory involvement,” the authors wrote.
Jiao K, Dong J, Luo S, et al. High-risk screening of late-onset Pompe disease: a different early portrait in China. Front Neurol. Published online September 27, 2022. doi:10.3389/fneur.2022.965207