Capturing Key MG-symptoms Using Smartphone Recordings.

Inclusion Criteria:

1. Age ≥ 18 years

2. Ability to understand the requirements of the study and provide written informedconsent.

Inclusion Criteria for MG participants only:

1. A clinical diagnosis of myasthenia gravis (ocular or generalized) with the typicalfluctuating muscle weakness and at least one of the following:

• a positive serologic test for AChR or MuSK antibodies;

• an abnormal electrodiagnostic test: repetitive nerve stimulation (RNS) orsingle-fiber electromyography (SFEMG).

2. MGFA Clinical Classification of disease severity I-IV.

3. Subjects have at least one of the symptoms of interest (namely dysarthria,dysphonia, proximal arm fatigue and/or ptosis).

Inclusion Criteria for non-MG participants only

1. Subjects are not diagnosed with and have no clinical suspicion of MG.

2. Subjects do not have a medical history of any of the symptoms of interest (namelydysarthria, dysphonia, proximal arm fatigue and/or ptosis).

Exclusion Criteria:

1. Not willing to be audio-recorded for the study assessments.

2. Not willing to be video-recorded for the study assessments.

3. Subjects currently taking part in a clinical trial of an Investigational MedicinalProduct.

4. Subjects who have used an immediate release pyridostigmine-based medication in the 12 hours prior to their participation and participants on prolonged releasepyridostigmine.

5. Subjects have cognitive or physical limitations that, in the opinion of theinvestigator, limits the subject's ability to complete study procedures/

Exclusion Criteria for MG participants only:

1. Subjects with an upper-limb amputation or who are non-verbal.

2. Subjects with a diagnosed neurological disease resulting in muscle weakness, otherthan MG.

Exclusion Criteria for non-MG participants only:

1. Limitation of upper limb mobility or speech impairment of any cause.