Inclusion Criteria:

• Patient and/or parent or legal guardian must be willing and have the ability to provide written informed consent for participation in the study.
• Male or Female
• Any age
• Diagnosis of NM which in most cases includes having a disease-causing variant/s in one of the known NM causative genes and a consistent clinical phenotype.

Exclusion Criteria:

• Any confirmed chronic or acute condition or disease affecting any system(s), which could interfere with the results of the study and/or the compliance with the study procedures. This will be subject to the clinical judgement of the Chief Investigator (CI) and/or the Principal Investigator (PI).
• Clinically significant medical finding on the physical examination other than NM that, in the judgment of the Investigator, will make the patient unsuitable for participation in, and/or completion of the study procedures.
• Participants of ongoing (interventional) clinical trials that assess the efficacy of potential treatments will be excluded as assessments need to be done on the basis that represent the natural progression of NM.
• Safety concerns. This includes anything that might put the participant and/or their Parent(s) or Guardian(s) at risk through participating in the study potentially including but not limited to: Safeguarding concerns, Social Issues and Health issues.