Psoriasis is a chronic inflammatory skin disease whose pathogenesis and genetic background remain unclear. Considering that previous studies have suggested an association of psoriasis vulgaris (PV) and killer cell immunoglobulin-like receptors (KIRs), we typed 15 KIR genes and human leukocyte antigen (HLA)-Cw in 79 Brazilian Caucasoid patients with PV and 110 healthy controls by polymerase chain reaction (PCR) using sequence-specific oligonucleotides and sequence-specific primers. We did not observe a relevant increase in the frequency of the activating KIR2DS1 gene in the PV group [KIR2DS1, 46 of 79 cases (58.2%) vs 40 of 110 controls (36.4%)]. However, an association of KIR2DS1 with Cw*0602+ in 26.5% of PV patients was observed, while it was present in only 5.4% of controls. These results suggest that activating KIR2DS1 gene may not confer susceptibility to PV, and an association of KIR2DS1 gene with the HLA-Cw*0602+ was observed in these patients.

Li-Fraumeni syndrome is a rare inherited cancer syndrome characterised by the early onset of specific cancers. Li-Fraumeni syndrome (LFS) is associated with germline mutations in the tumour suppressor gene, TP53. This study reports the first cases of molecularly confirmed LFS germline mutations in sub-Saharan Africa. Three black African patients, all with LFS-associated cancers, were seen through the Clinical and Counselling Section of the Division of Human Genetics at the National Health Laboratory Service and University of the Witwatersrand in Johannesburg, South Africa, during 2011-2012. All three patients (two were related) were recruited into this research study. Sequence analysis of the coding region of the TP53 gene identified a Class IV (likely pathogenic) variant, c.326T > C (p.Phe109Ser), in the two related patients, and a known pathogenic mutation, c.1010G > A (p.Arg337His), also referred to as the Brazilian founder mutation, in the other patient. A confirmed diagnosis in these patients will assist in tailored medical management (it is recommended that individuals carrying a germline TP53 mutation avoid radiotherapy as this might cause secondary radiotherapy-induced malignancies) and in addition, genetic testing of at-risk family members can be offered. Very little is known and documented on LFS in African individuals. Despite the small number of patients in this study, the results support the need for diagnostic genetic testing for LFS in South Africa.