תרומת זרע וסוג דם

נאלצנו לקבל תרומת זרע. לצערי קיבלנו תורם שסוג הדם שלו הוא AB, בעוד אני O ובעלי B. הילדה בעלת סוג דם A. כשביררנו בבנק הזרע נאמר לנו שמוטציות כאלה מתרחשות לפעמים, ולכן אין להם בעיה לתת לנו תורם בעל סוג דם כזה. מכיוון שיש אצלנו אנשים בעלי ידע בנושא, במקרה של גילוי לא נוכל להמשיך ולהסתיר את האמת. לכן רציתי לבקש מקורות למידע רפואי בנושא. תודה

הנושא שהזכרת - מוטציה הגורמת לכך שצאצא יהיה בעל סוג דם שאינו מתאים להוריו - אפשרית (גם אם נדירה). הנושא מוזכר במאמרים הבאים: http://www.divorcenet.com/paternity/abo-blood.html http://www.bloodbook.com/inherited.html http://www.paternityangel.com/Articles_zone/Blood/BloodType4.htm אפשרות אחרת "להסביר" את המצב הקיים היא שהאב (בעלך) אינו B אלא AB שיש לו ביטוי מוחלש של A בבדיקות השגרתיות או שהוא תת קבוצה של A מטיפוס נדיר שלא מאותרת בבדיקות הרגילות - דבר שיכול להסביר מדוע הילד הוא A. ראי לדוגמה את הציטוט הבא שמסביר איך יכול להיוולד ילד O להורים AB ו- O: Genetic mechanism of blood group (ABO)-expression. Yoshida A. It has generally been believed that human blood group ABO is controlled by allelic ABO genes. However, this hypothesis has not yet been experimentally proven, and other possibilities such as the non-allelic gene model and the regulatory gene model for ABO locus have also been proposed. The genetic mechanisms of many unusual blood group expressions remain unanswered. Purification of human blood group N-acetylgalactosyltransferase (A-enzyme) which synthesizes A-substance, and blood group galactosyltransferase which is responsible for synthesis of B-substance, allows us to resolve these problems from an immuno-biochemical approach. It was found that rabbit antibody against-A-enzyme completely neutralized not only A-enzyme but also B-enzyme activity. Moreover, plasma from blood type O subjects contained an enzymatically inactive but immunologically cross-reactive material (CRM). Plasma from heterozygous AO and BO subjects also contained CRM, but plasma from homozygous AA and BB subjects did not contain CRM. These facts led us to conclude that the ABO genes are allelic in the strict sense, refuting other genetic models for ABO locus. Genotypes of phenotype A and B subjects can be unequivocally determined by examining the presence or absence of CRM in their plasma. Mechanism of the unusual blood group inheritance of Cis-AB (i.e., AB and/or O childbirth from AB X O parent) was elucidated by examining properties of the A and B enzymes, CRM in their plasma, and separation of active enzymes and CRM by affinity chromatography. It became clear that Cis-AB expressions in one family was due to unequal chromosomal crossing-over producing a single chromosome with the genes for A and B enzymes. In contrast, in the other two unrelated families, the Cis-AB expression was due to a structural mutation in A or B gene producing a single abnormal enzyme which was capable of transferring both GalNAc and Gal to H-substance. Mechanism of very weak B expression in a family with A1Bm character was studied. Plasma enzyme activity and kinetic characteristics of B-enzyme from the subjects was not different from that of normal. However, the A1Bm red cells contained a large amount of unoccupied H-sites which can be galactosylated in vitro and become B active. Examination of membrane components by isoelectric focussing revealed that blood group components of the A1Bm membranes were distinctively different from that of the usual membranes. Consequently, the weak B expression is not due to direct mutation of ABO locus, but due to a secondary consequence of genetic abnormality of a membrane component (or components) associated with blood group substances. ועוד ציטוט דומה: An unusual case of blood group ABO inheritance: O from AB X O. Oka Y, Niikawa N, Yoshida A, Matsumoto H. An unusual blood group inheritance, that is, a phenotype O child from AB X O parents, was found in a Japanese family. Since two other children from the parents are blood type B, this is not a case of Cis-AB inheritance. The mother is not blood A/B chimera, and normal levels of blood group N-acetylgalactosaminyltransferase (A-enzyme) and galactosyltransferase (B-enzyme) were detected in her plasma. Therefore, the mother is genetically true AB heterozygous. The two sons with phenotype B had normal levels of plasma B-enzyme, but had no A-enzyme, and the father and the daughter with phenotype O had neither A- nor B-enzyme in their plasma. The analyses of 24 genetic marker systems indicated that the O daughter was a true child of the parents. The affirmative probability of parentage on the O daughter was calculated to be .9999999917 by Bayes' theorem. We concluded that the genotype of the O daughter was not the usual 00, and that this rare O expression might be due to a new structural mutation or a deletion in either maternal A or B gene during oogenesis. ועוד: Genomic analysis of clinical samples with serologic ABO blood grouping discrepancies: identification of 15 novel A and B subgroup alleles. Olsson ML, Irshaid NM, Hosseini-Maaf B, Hellberg A, Moulds MK, Sareneva H, Chester MA. Blood Centre, University Hospital, Lund, Sweden. [email protected] Since the cloning in 1990 of complementary DNA corresponding to messenger RNA transcribed at the blood group ABO locus, polymorphisms and phenotype-genotype correlations have been reported by several investigators. Exons 6 and 7, constituting 77% of the gene, have been analyzed previously in samples with variant phenotypes but for many subgroups the molecular basis remains unknown. This study analyzed 324 blood samples involved in ABO grouping discrepancies and determined their ABO genotype. Samples from individuals found to have known subgroup alleles (n = 53), acquired ABO phenotypes associated with different medical conditions (n = 65), probable chimerism (n = 3), and common red blood cell phenotypes (n = 109) were evaluated by ABO genotype screening only. Other samples (n = 94) from apparently healthy donors with weak expression of A or B antigens were considered potential subgroup samples without known molecular background. The full coding region (exons 1-7) and 2 proposed regulatory regions of the ABO gene were sequenced in selected A (n = 22) or B (n = 12) subgroup samples. Fifteen novel ABO subgroup alleles were identified, 2 of which are the first examples of mutations outside exon 7 associated with weak subgroups. Each allele was characterized by a missense or nonsense mutation for which screening by allele-specific primer polymerase chain reaction was performed. The novel mutations were encountered in 28 of the remaining 60 A and B subgroup samples but not among normal donors. As a result of this study, the number of definable alleles associated with weak ABO subgroups has increased from the 14 previously published to 29. ועוד אחד: Membrane abnormality in red blood cells with weak type B expression. Yoshida A, Fujii H, Dave V, Cozant MJ, Morel PA. The mechanisms of unusually weak blood group (A and B) expressions are not yet well understood. We examined properties of blood group galactosyltransferase (B-enzyme) and characteristics of red cell membrane components obtained from family members with A2Bm character. B-enzyme activity of the A1Bm plasma is in normal range, and kinetic properties (i.e., Km for UDP-Gal, Km for 2'-fucosyllactose, and pH optima) of B-enzyme from the A1Bm subjects are identical to that of normal B-enzyme. When A1Bm red cell were incubated with UDP-Gal and B-enzyme, the cells became strongly agglutinable with anti-B. When A1Bm membranes were incubated with B-enzyme or A-enzyme (i.e., blood group N-acetylgalactosaminyltransferase) and the appropriately labeled nucleotide sugar (UDP-Gal3H for B-enzyme and UDP-GalNAc3H for A-enzyme), significant incorporation of the sugar was observed. The amounts of the sugar incorporated into A1Bm membranes were about 40%-50% of that incorporated into O membranes at saturation, indicating that about one-half of H-sites remained unglycosylated in A1Bm red cells. Examination of radioactive components by isoelectric focussing revealed that the labeled components of A1Bm membranes were distinctively different from that of O membranes. Therefore, one can conclude that the weak B expression is not due to direct mutation of ABO locus, but due to a secondary consequence of genetic abnormality of a membrane component (or components) associated with blood group substances ועוד אחד: Mosaicism of red cell ABO type without recognizable cause. Borley R, Hsu TC, Sawitsky A, Johnson CL, Marsh WL. A 19-year old woman has been found whose red cells are a mixture of groups A1B (60%) and A1 (40%). Tests for many other genetic markers show no other evidence of mosaicism. She is not a twin and her parents and a sib are of normal ABO type. The cause of her dual population of red cells cannot be established, but may be an effect of somatic crossing over or mutation.