1. ¹Institute of Internal Medicine, Catholic University, Rome, Italy
2. ²Department of Biology "Enrico Calef", Tor Vergata University, Rome, Italy
3. ³Department of Dermatology, Tor Vergata University Hospital, Rome, Italy
4. ⁴Department of Paediatrics, University Hospital, Messina, Italy
5. ⁵Department of Internal Medicine, "V Cervello" Hospital, Palermo, Italy
6. ⁶Nutrition Unit, S Eugenio Hospital, Rome, Italy

Correspondence: Professor Domenico Frezza, Department of Biology "Enrico Calef", Tor Vergata University, Viale dell'Università, Rome 00133, Italy. E-mail: frezza@uniroma2.it

⁷These authors contributed equally to this work

Received 8 March 2007; Revised 6 November 2007; Accepted 14 December 2007; Published online 6 March 2008.

Abstract

The enhancer DNase-hypersensitive region 1,2 (HS1,2), a member of the Ig heavy-chain 3' regulatory region (3'RR) cluster, is active in human B cells transfected with reporter genes and in mouse is activated in late maturation. HS1,2-A contains binding sites for several transcription factors. There are four known alleles, that is, ^*1, ^*2, ^*3, and ^*4, which differ in their lengths in transcription factor binding. We showed that in celiac disease the frequency of the ^*2 allele is increased. Both dermatitis herpetiformis (DH) and psoriasis can be associated with different frequencies with celiac disease. Thus, we further investigate the frequency of allele ^*2 in DH, plaque psoriatic, and psoriatic arthritis patients. HS1,2-A allele frequencies were investigated in 37 DH, 61 plaque psoriatic, 28 psoriatic arthritis patients, and 265 healthy donors, age- and sex-matched, from the same geographical area. The frequency of the ^*2 allele changes from 0.39 in controls to 0.63 in DH, 0.59 in plaque psoriasis and 0.75 in psoriatic arthritis (P between 10^-4–10^-5). Our data evidence an increased frequency of the ^*2 allele of HS1,2-A in these cutaneous immune-related disorders. We suggest a related genetic predisposition in these pathogeneses.