Cross-sectional study to characterize cohorts of children with asthma and healthy controls in terms of clinical features, physiological measurements and non-invasive measurement of biomarkers and develop phenotype handprints for children with severe asthma

Inclusion Criteria:

1. Parent / guardian must be able to give written informed consent prior to participation in the study, which includes ability to comply with the requirements and restrictions listed in the consent form. Informed consent must be obtained prior to undertaking any study procedures.
2. Assent should be obtained from all children in the study where appropriate.
3. Male or female subject aged between 1 - 17 years inclusive at screening.
4. The parent / guardian, or where appropriate the child must be able to read, comprehend, and write at a sufficient level to complete study related materials.
5. Subjects will be allowed to enrol in other studies while taking part on this study. However, Permission from the Scientific Board must be obtained to enrol or allow the continued participation of a subject enrolled in another study.

Exclusion Criteria:

1. As a result of medical interview, physical examination or screening investigation the physician responsible considers the child unfit for the study.
2. The subject has a history of drug or other allergy, which, in the opinion of the responsable physician, contra-indicates their participation.
3. Subject is female who is pregnant or lactating or up to 6 weeks post partum or 6 weeks cessation of breast feeding. If a woman is subsequently found to have been pregnant at the time of an assessment data from that assessment will not be included in the analyses
4. The child has participated within 3 months of the first dose in a study using a new molecular entity, or the first dose in any other study investigating drugs or having participated within three months in a study with invasive procedures. Any U-BIOPRED assessments should be deferred until 3 months after the first dose or invasive procedure. Permission from the Scientific Board must be obtained to enroll or allow the continued participation of a child enrolled in another study.
5. Those who, in the opinion of the investigator, have a risk of non-compliance with study procedures.
6. Prematurity ≤35 weeks gestation
7. The child had changed asthma medication within 4 weeks of the screening assessment(except those using the Symbicort maintenance and reliever therapy (SMART) regime)(assessment should be deferred)
8. History or current evidence of an upper or lower respiratory infection or symptoms (including common cold) within 2 weeks of baseline assessment (assessment should be deferred).
9. The child has had a severe exacerbation (requiring ER attendance or hospital admission and/or a course of high dose OCS for at least 3 days duration) within 4 weeks of the baseline assessment (assessment should be deferred).

• Severe school aged asthma cohort: persistent symptoms or frequent severe exacerbations or persistent airflow limitation
• Mild-moderate school aged asthma cohort: controlled or partially controlled asthma symtomps
• Severe pre school wheeze cohort: persistent symptoms or frequent severe exacerbations
• Mild-moderate pre school wheeze cohort: controlled symptoms or partially controlled