RT Journal Article SR Electronic T1 Why we should care about ultra-rare disease JF European Respiratory Review JO EUROPEAN RESPIRATORY REVIEW FD European Respiratory Society SP 101 OP 103 DO 10.1183/16000617.0017-2016 VO 25 IS 140 A1 Sergio Harari YR 2016 UL http://err.ersjournals.com/content/25/140/101.abstract AB