Beyond human leukocyte antigen class i antigens: hereditary hemochromatosis gene mutations in recurrent aphthous oral ulcers and Behcet disease in the South of Tunisia

Objective: The aim of this work was to establish human leukocyte antigen [HLA] class I and hereditary hemochromatosis gene [HFE] mutation associations with recurrent aphthous oral ulcers [RAOU] and Behcet disease [BD] in a cohort of Southern Tunisian patients

Subjects and Methods: A total of 232 patients with RAOU and 123 healthy controls [HCs] were enrolled in this study. The patients were divided into 2 groups based on the presence [BD+: n = 62] or absence of BD [BD - , n = 170]. In the BD+ group, 28 patients had severe manifestations of BD. In the BD- group, RAOU was isolated in 81 patients, associated with mucocutaneous manifestations in 58 and with joint symptoms in 25. Complement-dependent microlymphocytotoxicity assay and polymerase chain reaction-restriction fragment length polymorphism were used to study HLA class I polymorphism and HFE mutations, respectively

Results: HLA-B51 was positively associated with BD, particularly in those with severe manifestations. No association was detected with HLA class I polymorphism among the BD group. Based on stratification to clinical manifestations, the isolated RAOU was negatively associated with HLA-A1 with a difference close to significance [12 [14.81%] vs. 32 [26.02%] in HCs; p = 0.06]. Furthermore, patients with mucocutaneous features had a higher frequency of HLA-B51 [14, 24.14%] than patients without mucocutaneous involvement [11, 11.37%]. Considering HFE mutations, patients with isolated RAOU had a higher frequency of H63D when compared with other subgroups, especially after limiting the comparison to 27 patients of at least 5 years of follow up

Conclusion: This study showed that, unlike BD, RAOU were not associated with HLA-B51. Moreover, we suggest that H63D mutation was positively associated with isolated RAOU

Application of victims' fingernails in Forensic DNA analysis.

DNA extracted from the victims’ fingernails may assist in the identification of the aggressor. Fingernails were collected from 8 victims, and were subjected to DNA extraction using the Kit « Tissue and Hair Extraction Kit (Promega) ». All samples were typed for 15 autosomal short tandem repeats and for amelogenin using the Kit « Powerplex TM16 system (Promega) » and the ABI Prism 310 DNA sequencer. The profiles obtained were compared with those achieved by similar typing of victims’ and suspects’ blood. In two Forensic investigations, mixed genotypes were detected in DNA extracted from the nails: Alleles originating from the victim were coamplified with other alleles that matched the suspect’s genotypic profile. This indicated that victims’ fingernails contained biological material (blood, epithelial cells) originating from the suspect. Our results confirmed the usefulness of the nails as a specimen for forensic identification of the aggressor.