The aim of this study was to evaluate the activity of daily living (
ADL) and surgical interventions in patients with
mucopolysaccharidosis IVA (
MPS IVA). The factor(s) that affect
ADL are age, clinical phenotypes, surgical interventions,
therapeutic effect, and body mass index. The
ADL questionnaire comprises three domains: "Movement," "Movement with cognition," and "Cognition." Each domain has four subcategories rated on a 5-point scale based on the level of assistance. The questionnaire was collected from 145 healthy controls and 82 patients with
MPS IVA. The patient cohort consisted of 63 severe and 17 attenuated phenotypes (2 were undefined); 4 patients treated with
hematopoietic stem cell transplantation (HSCT), 33 patients treated with
enzyme replacement therapy (ERT) for more than a year, and 45 untreated patients.
MPS IVA patients show a decline in
ADL scores after 10years of age. Patients with a severe phenotype have a lower
ADL score than healthy control subjects, and lower scores than patients with an attenuated phenotype in domains of "Movement" and "Movement with cognition." Patients, who underwent HSCT and were followed up for over 10years, had higher
ADL scores and fewer surgical interventions than untreated patients.
ADL scores for ERT patients (2.5years follow-up on average) were similar with the-age-matched controls below 10years of age, but declined in older patients. Surgical frequency was higher for severe phenotypic patients than attenuated ones. Surgical frequency for patients treated with ERT was not decreased compared to untreated patients. In conclusion, we have shown the utility of the proposed
ADL questionnaire and frequency of surgical interventions in patients with
MPS IVA to evaluate the clinical severity and therapeutic efficacy compared with age-matched controls.