Rheumatoid arthritis in an adult patient with mosaic distal 18q-,

Ring chromosome 18 has a highly variable phenotype, depending on the extent of distal arm deletions. It is most commonly presented as a combination of 18pand distal 18qsyndrome. IgA deficiency and autoimmune diseases have been previously described in these patients. Seven cases of juvenile rheumatoid arthritis (JRA) have been reported. Here we report the first case of late onset rheumatoid arthritis (RA) in a 32 year old Dominican woman with hypothyroidism, vitiligo, IgA deficiency, interstitial lung disease (ILD), cystic bronchiectasis, and features consistent with 18pand distal 18q syndrome. Comparative genome hybridization analysis showed a del(18p11.21p11.32), dup(18q11.21-q22.1), and del(18q22.1-q23). Chromosomal analysis and fluorescence in situ hybridization showed three cell lines. One cell line was detected with a dicentric ring chromosome, another with duplication of the long arm and no short arm, and lastly a long arm terminal deletion of 18. The multiple autoimmune findings in our patient lends further support to the idea of loci on chromosome 18 playing a role in autoimmune disease expression. Late onset RA and ILD in a patient with chromosome 18 abnormalities are novel findings and are additional conditions to be aware of in this population. Shitij Arora ( ) Corresponding author: [email protected] No competing interests were disclosed. Competing interests: Chau A, Ramesh K, Jagannath AD and Arora S. How to cite this article: Rheumatoid arthritis in an adult patient with mosaic distal 18q-, 2017, :1940 (doi: 18pand dicentric ring chromosome 18 [version 1; referees: 2 approved with reservations] F1000Research 6 ) 10.12688/f1000research.11539.1 © 2017 Chau A . This is an open access article distributed under the terms of the , which Copyright: et al Creative Commons Attribution Licence permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The author(s) declared that no grants were involved in supporting this work. Grant information: 02 Nov 2017, :1940 (doi: ) First published: 6 10.12688/f1000research.11539.1 1 2 3 1 2 3 Referee Status: Invited Referees version 1 published 02 Nov 2017 1 2