Polymorphisms of KITLG, SPRY4, and BAK1 genes in patients with testicular germ cell tumors and individuals with infertility associated with AZFc deletion of the Y chromosome
MOLECULAR BIOLOGY
Authors: Nemtsova, M. V.; Ivkin, E. V.; Simonova, O. A.; Rudenko, V. V.; Chernykh, V. B.; Mikhaylenko, D. S.; Loran, O. B.
Abstract
Testicular cancer is the most common form of solid cancer in young men. Testicular cancer is represented by testicular germ cell tumors (TGCTs) derived from embryonic stem cells with different degrees of differentiation in about 95% of cases. The development of these tumors is related to the formation of a pool of male germ cells and gametogenesis. Clinical factors that are predisposed to the development of germ-cell tumors include cryptorchidism and testicular microlithiasis, as well as infertility associated with the gr/gr deletion within the AZFN locus. KITLG, SPRY4, and BAK1 genes affect the development of the testes and gametogenesis; mutations and polymorphisms of these genes lead to a significant increase in the risk of the TGCT development. To determine the relationship between gene polymorphisms and the development of TGCTs, we developed a system for detection and studied the allele and genotype frequencies of the KITLG (rs995030, rs1508595), SPRY4 (rs4624820, rs6897876), and BAK1 (rs210138) genes in fertile men, patients with TGCTs, and patients with infertility that have the AZFN deletion. A significant association of rs995030 of the KITLG gene with the development of TGCTs (p = 0.029 for the allele G, p = 0.0124 for the genotype GG) was revealed. Significant differences in the frequencies of the studied polymorphisms in patients with the AZFc deletion and the control group of fertile men were not found. We showed significant differences in the frequencies for the combination of all high-risk polymorphisms in the control group, patients with the AZFc deletion and patients with TGCTs (p (TGCTs-AZF-control) = 0.0207). A fivefold increase in the frequency of the combination of all genotypes in the TGCT group (p = 0.0116; OR = 5.25 [1.44aEuro'19.15]) and 3.7-fold increase was identified in patients with the AZFc deletion (p = 0.045; OR = 3.69 [1.11aEuro'12.29]) were revealed. The genotyping of patients with infertility caused by the AZFc deletion can be used to identify individuals with an increased risk of TGCTs.
Genetic determinants of hair, eye and skin pigmentation in Europeans
NATURE GENETICS
Authors: Sulem, Patrick; Gudbjartsson, Daniel F.; Stacey, Simon N.; Helgason, Agnar; Rafnar, Thorunn; Magnusson, Kristinn P.; Manolescu, Andrei; Karason, Ari; Palsson, Arnar; Thorleifsson, Gudmar; Jakobsdottir, Margret; Steinberg, Stacy; Palsson, Snaebjorn; Jonasson, Fridbert; Sigurgeirsson, Bardur; Thorisdottir, Kristin; Ragnarsson, Rafn; Benediktsdottir, Kristrun R.; Aben, Katja K.; Kiemeney, Lambertus A.; Olafsson, Jon H.; Gulcher, Jeffrey; Kong, Augie; Thorsteinsdottir, Unnur; Stefansson, Kari
Abstract
Hair, skin and eye colors are highly heritable and visible traits in humans. We carried out a genome-wide association scan for variants associated with hair and eye pigmentation, skin sensitivity to sun and freckling among 2,986 Icelanders. We then tested the most closely associated SNPs from six regions-four not previously implicated in the normal variation of human pigmentation-and replicated their association in a second sample of 2,718 Icelanders and a sample of 1,214 Dutch. The SNPs from all six regions met the criteria for genome-wide significance. A variant in SLC24A4 is associated with eye and hair color, a variant near KITLG is associated with hair color, two coding variants in TYR are associated with eye color and freckles, and a variant on 6p25.3 is associated with freckles. The fifth region provided refinements to a previously reported association in OCA2, and the sixth encompasses previously described variants in MC1R.