STOPPA stands for "Swedish Twin study On Perinatal characteristics to Prevent Asthma". The aim of the STOPPA study (Swedish Twin study On Prediction and Prevention of Asthma) is to identify environmental and genetic factors as determinants for asthmatic disease.
Asthma is a common childhood disease and several risk factors have been identified; however, the impact of genes and environment is not fully understood. Based on the Child and Adolescent Twin Study in Sweden (CATSS), which is part of the Swedish Twin Registry, parental interview at 9 or 12 years and an asthma and/or wheezing algorithm, we identified monozygotic (MZ) and dizygotic (DZ) same-sexed twin pairs. The twin pairs were classified as asthma concordant (ACC), asthma discordant (ADC) and healthy concordant (HCC). A sample of 9- to 14-year-old twins and their parents were invited to participate in a clinical examination.
Background characteristics were collected in questionnaires and obtained from the National Health Registers. A clinical examination was performed to test lung function and capacity (spirometry with reversibility test and exhaled nitric oxide) and collect blood (serology, genomics, epigenomics, transcriptomics and proteomics), urine (metabolites), feces (microbiota), and saliva (cortisol).
In total, 376 twin pairs (752 individual twins) completed the study, response rate 52%. All participating twins answered the questionnaire and >90% participated in lung function testing, blood-, and saliva sampling. We have a number of ongoing and planned analyses in STOPPA and contribute towards consortia such as the Pregnancy And Childhood Epigenetics (PACE) and the Genomic Agregation Project in Sweden (GAPS) . We welcome fellow researchers to novel and innovative collaborations on research questions using data derived from the STOPPA cohort.