Hypomelanosis of Ito with a trisomy 2 mosaicism: a case report

Introduction: Hypomelanosis of Ito is a rare neurocutaneous disorder, characterized by streaks and swirls of hypopigmentation following the lines of Blaschko that may be associated to systemic abnormalities involving the central nervous system and musculoskeletal system. Despite the preponderance of reported sporadic hypomelanosis of Ito, few reports of familial hypomelanosis of Ito have been described. Case presentation: A 6-month-old Caucasian girl presented with unilateral areas of hypomelanosis distributed on the left half of her body and her father presented with similar mosaic hypopigmented lesions on his upper chest. Whereas both blood karyotypes obtained from peripheral lymphocyte cultures were normal, a 16% trisomy 2 mosaicism was found in cultured skinfibroblasts derived from a hypopigmented skin area of her father. Conclusions: Familial cases of hypomelanosis of Ito are very rare and can occur in patients without systemic involvement. Hypomelanosis of Ito constitutes a non-specific diagnostic definition including different clinical entities with a wide phenotypic variability, either sporadic or familial. Unfortunately, a large number of cases remain misdiagnosed due to both diagnostic challenges and controversial issues on cutaneous biopsies in the pediatric population

Pathway-Based Analysis of a Melanoma Genome-Wide Association Study: Analysis of Genes Related to Tumour-Immunosuppression

Systemic immunosuppression is a risk factor for melanoma, and sunburn-induced immunosuppression is thought to be causal. Genes in immunosuppression pathways are therefore candidate melanoma-susceptibility genes. If variants within these genes individually have a small effect on disease risk, the association may be undetected in genome-wide association (GWA) studies due to low power to reach a high significance level. Pathway-based approaches have been suggested as a method of incorporating a priori knowledge into the analysis of GWA studies. In this study, the association of 1113 single nucleotide polymorphisms (SNPs) in 43 genes (39 genomic regions) related to immunosuppression have been analysed using a gene-set approach in 1539 melanoma cases and 3917 controls from the GenoMEL consortium GWA study. The association between melanoma susceptibility and the whole set of tumour-immunosuppression genes, and also predefined functional subgroups of genes, was considered. The analysis was based on a measure formed by summing the evidence from the most significant SNP in each gene, and significance was evaluated empirically by case-control label permutation. An association was found between melanoma and the complete set of genes (pemp = 0.002), as well as the subgroups related to the generation of tolerogenic dendritic cells (pemp = 0.006) and secretion of suppressive factors (pemp = 0.0004), thus providing preliminary evidence of involvement of tumour-immunosuppression gene polymorphisms in melanoma susceptibility. The analysis was repeated on a second phase of the GenoMEL study, which showed no evidence of an association. As one of the first attempts to replicate a pathway-level association, our results suggest that low power and heterogeneity may present challenges

Reduced-Complexity Soft Demapping for Turbo-Equalization

International audienc

Reflectance confocal microscopy of mucosal pigmented macules: a review of 56 cases including 10 macular melanomas

BACKGROUND: Although most mucosal pigmented macules are benign, it can be clinically challenging to rule out an early melanoma. Reflectance confocal microscopy (RCM) is a noninvasive imaging technique useful in discriminating between benign and malignant skin lesions. OBJECTIVES: To describe the confocal aspects of benign and malignant mucosal pigmented macules with histopathological correlations. METHODS: We retrospectively reviewed the confocal images of 56 labial or genital pigmented macules including 10 macular melanomas. According to the retrospective nature of the study, we evaluated the recorded images chosen by the physicians that performed the RCM examination for each case. RESULTS: In benign macules, the most frequently observed pattern was a ringed pattern characterized by round or polycyclic papillae, with a hyper-reflective basal layer; another pattern was characterized by sparse bright dendritic cells in the basal layer, the basal epithelial cells being otherwise less reflective. Roundish cells, a high density of dendritic cells with atypias and intraepithelial bright cells were clues to the presence of malignancy. CONCLUSIONS: Reflectance confocal microscopy seems to be a valuable tool to noninvasively differentiate benign from malignant mucosal pigmented macules and target biopsies in cases of equivocal features