Hair heterochromia may be caused by different mechanisms. At clinical work, we found a Chinese boy whose hair colour gradually turned to red. We record the diagnosis and treatment process and follow-up situation, finally find that altered hair colour phenotype is due to MC1R genetic mutations, rather than zinc deficiency. This rarely red hair colour phenotype improve our understanding of hair heterochromia caused by genetic mutations.

The risk of keratinocyte cancer is determined by intrinsic and extrinsic factors, which also influence skin aging. Few studies have linked skin aging and UV exposure with the incidence of non-melanoma skin cancer (NMSC). We evaluated signs of actinic skin damage and aging, individual UV burden, and melanocortin-1 receptor (MC1R) variants. A total of 194 organ transplant recipients (OTR) who suffered from NMSC were compared to 194 tumor-free controls matched for gender, age, type of transplanted organ, post-transplantation (TX) period, and immunosuppressive therapy. Compared with the cases, the controls scored higher in all skin aging scores and there were no differences in UV burden except for intentional whole-body UV exposure for specific UV scenarios and periods of life in favor of cases. The number of NMSCs correlated with all types of skin aging scores, the extent of intentional sun exposure, older age, longer post-TX period, shorter interval from TX to first NMSC, and specific MC1R risk groups. Multivariable models revealed a 7.5-fold risk of developing NMSC in individuals with actinic keratosis; 4.1- or 3.6-fold in those with green or blue eyes, respectively; and a 1.9-fold increased risk in the MC1R medium- + high-risk group. In the absence of skin aging contributing to NMSC development, certain MC1R risk types may identify OTR at risk for high tumor burden.

Melanocortin 1 receptor (MC1R) gene variants are a major contributor to pigmentation characteristics and the modulation of sporadic basal cell carcinoma (BCC) risk. This is a hospital-based, case-control study to investigate the association of MC1R variants and pigmentary characteristics with the risk of BCC development in a Southern European population in Greece. In total, 141 patients with BCC and 166 controls were studied. Increased BCC risk was found for the presence of 2 or more MC1R variants (OR:3.07, 95% CI:1.13-8.34), or 2 or more variants of which at least 1 was major function (OR:7.15, 95% CI:1.37-5.52), after adjustment for the \'red hair colour\' (RHC) phenotype. Increased BCC risk persisted in the presence of 2 or more MC1R variants (OR:4.15, 95% CI:1.35-12.72), after adjustment for potential confounding factors including skin color (P:0.237) and atypical nevi (OR:9.57, 95% CI:2.19-41.81, P:0.003). MC1R genotype is a risk factor for the development of BCC in Greek patients independently of pigmentary characteristics, and the combination of MC1R variants may modulate this risk.