Short Communication Analysis of polymorphic sites in the promoter of the nitric oxide synthase 2 gene in Brazilian patients with leprosy I. J. T. Messias-Reason*, H. van Tong† & T. P. Velavan† Summary Leprosy is one of the most neglected infectious tropi- cal diseases of the skin and the nerves caused by the intracellular pathogen Mycobacterium leprae. The inducible NOS isoform encoded by NOS2A plays a vital role in host defence against bacterial infections. The functional promoter polymorphisms in NOS2A are associated with various autoimmune and infectious diseases. We investigated the association of NOS2A variants with progression of leprosy in a Brazilian cohort including 221 clinically classified patients and 103 unrelated healthy controls. We observed a novel variant ss528838018A/G in the promoter region at position À6558. The other functional variants were observed with low frequency of minor allele (<0.005). NOS2A promoter variant (À954G/C) was not observed in Brazilian populations, and the new observed promoter variant (ss528838018A/G) as well as other promoter variants were not associated with any clinical forms of leprosy in the Brazilian populations. Introduction Leprosy, a disease caused by Mycobacterium leprae, is a foremost cause of permanent disability in the world and predominantly affects the poor marginalized peo- ple in the world. Although not fatal, the chronic symp- toms often afflict individuals in their most productive stage of life and therefore impose a significant social and economic burden on society (Britton & Lock- wood, 2004). Despite eradication programmes, the new case and prevalence rate remain consistent, with 181 941 registered and 219 075 new cases detected during 2011, and the prevalence of leprosy is highly distributed in several developing countries in Asia, Africa and South America esp. in Brazil (WHO Fact sheet N°101, 2012). The development of leprosy com- prises a wide range of manifestations from leproma- tous leprosy to tuberculoid leprosy depending upon the cellular immune response against the Mycobacte- rium (Britton & Lockwood, 2004; Monot et al., 2009). In recent years, plethora of studies has provided increasing evidence that variability in host responsive- ness to leprosy infections has a strong genetic basis. Several genetic variants have been shown to associate with resistance or susceptibility to leprosy in different geographical populations (Mira et al., 2003; de Mes- sias-Reason et al., 2007, 2009; Zhang et al., 2009, 2011; Ali et al., 2012; Boldt et al., 2013; Marcinek et al., 2013; Shinde et al., 2013). Nitric oxide (NO) is a pleiotropic molecule that plays a vital role in host defence against bacterial and parasitic infections (Kun et al., 2001; Marriott et al., 2007). The inducible NOS isoform (iNOS or NOS2) expression is regulated at the transcription level and represents a vital path- way for nitric oxide production in response to injury, inflammation or infection (Bogdan, 2001). The human nitric oxide synthase (NOS2) gene located in the chro- mosome 17q11.2-12 is regulated primarily at the tran- scriptional level by the action of inflammatory cytokines and toxins (Kun et al., 2001; Coia et al., 2005). NOS2 was demonstrated to influence the inflammatory response to bacterial lipopolysaccharides (Speyer et al., 2003), and studies have shown that NOS2 was expressed in granulomas of borderline leprosy patients(Schon et al., 2001). The presence of promoter polymorphisms in NOS2 has vital implica- tions on a wide array of autoimmune and infectious diseases, including M. tuberculosis (Gomez et al., 2007; Velez et al., 2009) afflicting different world populations(Qidwai & Jamal, 2010). Especially three promoter polymorphisms were demonstrated to trans- criptionally deregulate and alter the level of the gene product. Earlier studies have demonstrated that NOS2A variant À954G/C and other promoter variants * Laborat orio de Imunopatologia Molecular, Departamento de Patolo- gia M edica, Hospital de Cl  ınicas, Universidade Federal do Paran a, Cu- ritiba, Brazil and † Institute of Tropical Medicine, University of T€ ubingen, T€ ubingen, Germany Received 6 August 2013; revised 26 November 2013; accepted 19 December 2013 Correspondence: Dr Thirumalaisamy P Velavan, Institute of Tropical Medicine, Wilhelmstraße 27, 72074 T€ ubingen, Germany. Tel: +49 7071 2985981; Fax: +49 7071 294684; E-mail: velavan@medizin. uni-tuebingen.de © 2014 John Wiley & Sons Ltd International Journal of Immunogenetics, 2014, 41, 231–235 231 doi: 10.1111/iji.12108