Pompe's Disease
Conditions
Brief summary
Pompe's disease is a very rare condition which causes weakness of the respiratory muscles and may therefore cause symptoms of breathlessness or even respiratory failure, requiring the use of a ventilator at night. Recently a treatment for this condition has become available as well as a simple diagnostic test. However, we believe it is possible that there are patients with this condition who are presently undiagnosed attending respiratory clinics. We would like to complete an observational study of patients with respiratory muscle weakness of an unknown cause, who are attending respiratory clinics at two London centres, to determine whether patients attending these services have undiagnosed Pompe's disease.
Detailed description
Participation in the study will involve taking measurements of respiratory muscle strength, lower limb strength and collecting blood samples to test for enzymes which relate to Pompe's disease. These measures will be completed during a routine clinic visit. Participation will also involve the study coordinator accessing medical notes to gain information about disease history. The study aims to collect information about the number of patients attending respiratory clinics with undiagnosed Pompe's disease and the characteristics of these patients so that other specialist services could use these criteria to identify patients who may benefit from investigations and treatment. If any participants are diagnosed with Pompe's disease and could benefit from treatment medical staff would refer them for treatment at local UK centres.
Interventions
Prospective observational study collecting data during a clinic vist including measurement of respiratory muscle strength, respiratory failure, lung function, physical performance and blood testing for enzymes related to Pompe's disease and muscle function.
Sponsors
Genzyme, a Sanofi Company
Royal Brompton & Harefield NHS Foundation Trust
Study design
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Patients presenting to home mechanical ventilation or other respiratory clinics: who are over 18 years old with unexplained respiratory muscle weakness with breathlessness and/or type II respiratory failure which may be treated by a ventilator which is: unexplained by a known pulmonary disease, radiological abnormality or distortion of body hiatus (e.g scoliosis or massive obesity defined as BMI \> 50 kg/m2), associated with a restrictive ventilatory defect or associated with unexplained muscle weakness.
Exclusion criteria
respiratory muscle weakness confirmed to be due to another cause known to have Pompe's disease at time of referral
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The prevalence of undiagnosed adult onset Pompes disease. This will be assessed through dry blood spot testing measuring α-glucosidase (GAA) deficiency and the Activity Ratio +/Acarbose. | 12 months | dry blood spot testing |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| CK levels | 12 months | blood tests |
| Respiratory muscle strength | 12 months | Using sniff nasal inspiratory pressure, spirometry in lying and sitting, maximal inspiratory and expiratory mouth pressure |
| Respiratory failure | 12 months | Blood gases |
| Muscle weakness | 12 months | performance on the short physical performance battery |
| Disease history | 12 months | review of notes to establish duration of symptoms, time interval between presentation and referral to secondary care and any signs of respiratory failure or respiratory muscle weakness at presentation. |
Contacts
Primary ContactMichael Polkey
Outcome results
None listed