When to consider genetic testing for COPA syndrome
| Pulmonary features |
| Evidence of follicular bronchiolitis or cysts |
| Diffuse alveolar haemorrhage |
| Extrapulmonary features |
| Early age of onset (<12 years) |
| Family history of disease |
| Positive for ANA or ANCA, ±RF |
| Arthritis |
Consider targeted sequencing for exons 8–9 of COPA in patients with one pulmonary feature and two extrapulmonary features, and strongly consider sequencing in patients with one pulmonary and three extrapulmonary features. ANA: anti-nuclear antibody; ANCA: anti-neutrophil cytoplasmic antibody; RF: rheumatoid factor.