[Late onset Pompe disease: an analysis of 19 patients from Mexico]

Pompe disease (PD) is a rare metabolic myopathy with an ample and heterogeneous clinical spectrum, particularly late onset PD (LOPD), which is characterized by appearance at older age and slower disease progression, leading to diagnostic confirmation difficulty and delay.

To describe the genotype and clinical characteristics of Mexican patients with LOPD.

Clinical information from 19 Mexican patients with LOPD confirmed with enzyme activity and GAA gene analysis was reviewed. Genetic information of our population was crossed with international genetic databases.

Median age between onset of symptoms and diagnosis was 19 years (range 2-43) and diagnostic confirmation 36 years (range 9-52). Most frequently referred symptoms were proximal axial weakness (n = 17; 89.5%), waddling gait (n = 17; 89.5%) and hyperlordosis (n = 7; 36.8%). Sixteen patients (84.2%) were evaluated with electromyography; a myopathic pattern was reported in 11 (57.8%), but only in 5 patients (26%) paraspinal muscle evaluation was included. The most pathogenic mutations in our group were c.-32-13T>G, c.1799G>A and c.1082C>T.

Similar to other international publications, LOPD in Mexico is clinically heterogeneous; patients may delay years before diagnosis is established. Axial and proximal weakness is the most frequent clinical feature; thus, electromyography with paraspinal muscle evaluation is essential. Except for one, the mutations found in our patients have been previously reported in PD genetic databases.