The last decade has witnessed important advances in our understanding of the genetics of pigmentation in European populations, but very little is known about the genes involved in skin pigmentation variation in East Asian populations. Here, we present the results of a study evaluating the association of 10 Single Nucleotide Polymorphisms (SNPs) located within 5 pigmentation candidate genes (OCA2, DCT, ADAM17, ADAMTS20, and TYRP1) with skin pigmentation measured quantitatively in a sample of individuals of East Asian ancestry living in Canada. We show that the non-synonymous polymorphism rs1800414 (His615Arg) located within the OCA2 gene is significantly associated with skin pigmentation in this sample. We replicated this result in an independent sample of Chinese individuals of Han ancestry. This polymorphism is characterized by a derived allele that is present at a high frequency in East Asian populations, but is absent in other population groups. In both samples, individuals with the derived G allele, which codes for the amino acid arginine, show lower melanin levels than those with the ancestral A allele, which codes for the amino acid histidine. An analysis of this non-synonymous polymorphism using several programs to predict potential functional effects provides additional support for the role of this SNP in skin pigmentation variation in East Asian populations. Our results are consistent with previous research indicating that evolution to lightly-pigmented skin occurred, at least in part, independently in Europe and East Asia.
Background Type 2 diabetes (T2D) is influenced by diverse environmental and genetic risk factors. Metabolic syndrome (MS) increases the risk of cardiovascular disease and diabetes. We analysed 14 cases of polymorphisms located in 10 candidate loci, in a sample of patients with T2D and controls from Mexico City.
Most living organ donations are from genetically or emotionally related donors. Although some transplant centers are willing to accept donations from living anonymous kidney donors (LAKDs), very few centers will accept donations from living anonymous liver donors (LALDs). The difference in acceptance rates is primarily due to the greater risk in liver donation, which is estimated to be 10-fold that of the risk in kidney donation. We present a case of donation from a LALD, the first reported in Canada. There are currently no established standards for LALDs. Our criteria for the ethical acceptability of LALDs require such donors to be physically healthy, mentally competent, altruistic, highly motivated, well-informed and able to give voluntary consent to donation. Another major ethical criterion is that the likely psychological benefit to the LALD balances the physical risks. Our case demonstrates that transplants from LALDs are medically successful and ethically justified under certain conditions.
Our understanding of the genetic architecture of iris color is still limited. This is partly related to difficulties associated with obtaining quantitative measurements of eye color. Here we introduce a new automated method for measuring iris color using high resolution photographs. This method extracts color measurements in the CIE 1976 L*a*b* (CIELAB) color space from a 256 by 256 pixel square sampled from the 9:00 meridian of the iris. Color is defined across three dimensions: L* (the lightness coordinate), a* (the red-green coordinate), and b* (the blue-yellow coordinate). We applied this method to a sample of individuals of diverse ancestry (East Asian, European and South Asian) that was genotyped for the HERC2 rs12913832 polymorphism, which is strongly associated with blue eye color. We identified substantial variation in the CIELAB color space, not only in the European sample, but also in the East Asian and South Asian samples. As expected, rs12913832 was significantly associated with quantitative iris color measurements in subjects of European ancestry. However, this SNP was also strongly associated with iris color in the South Asian sample, although there were no participants with blue irides in this sample. The usefulness of this method is not restricted only to the study of iris pigmentation. High-resolution pictures of the iris will also make it possible to study the genetic variation involved in iris textural patterns, which show substantial heritability in human populations.
Despite the success of transplantation, many transplant candidates and transplant recipients die each year. Some die awaiting transplants and some die months or years after receiving an organ. Quality end-of-life care can play a valuable role in easing the impact of death and dying in transplantation, as it focuses on enhancing patients' quality of life near death. Quality end-of-life care recognizes the values and preferences of patients and their families, and involves a process of shared decision making about patients' healthcare treatment in collaboration with healthcare practitioners. Advance care planning involves discussions with patients about their wishes and values about care, in the event that the patient becomes incapable of making such decisions. This article focuses on the application to transplantation of quality end-of-life care and advance care planning and identifies the effects that death and dying of transplant patients have on others. The information herein encourages healthcare practitioners to view and deliver quality end-of-life care as part of transplant patients' overall treatment management.
Despite the success of transplantation, many transplant candidates and transplant recipients die each year. Some die awaiting transplants and some die months or years after receiving an organ. Quality end-of-life care can play a valuable role in easing the impact of death and dying in transplantation, as it focuses on enhancing patients' quality of life near death. Quality end-of-life care recognizes the values and preferences of patients and their families, and involves a process of shared decision making about patients' healthcare treatment in collaboration with healthcare practitioners. Advance care planning involves discussions with patients about their wishes and values about care, in the event that the patient becomes incapable of making such decisions. This article focuses on the application to transplantation of quality end-of-life care and advance care planning and identifies the effects that death and dying of transplant patients have on others. The information herein encourages healthcare practitioners to view and deliver quality end-of-life care as part of transplant patients' overall treatment management.
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