Vox Sang. 35: 176-180 (1978)
Unusual Inheritance in the ABO Blood Group System: A Group 0 Child from A Group A2B Mother Maria Dolores Valdes, Caroline Zoes and Alice Froker Department o f Pathology and Laboratory Medicine, Evanston Hospital, Evanston, 111.
Abstract. A serologically typical group A2B mother with no unusual anti-A or anti-B agglutinins delivered a normal group 0 infant with no demonstrable A or B antigens. By the age of 1 year the child had developed anti-A and anti-B agglutinins. He had H antigen and secreted H substance in his saliva. A second groupochild has since been born. Although family studies were inconclusive, the most likely explanation is that the mother is a ci.v-AB. If this is the case, she differs from other reported cis-ABs in her apparently normal B antigen and the lack of anti-B antibodies in her serum.
Concepts of genetic mechanisms have evolved partly by systematic research and partly by study of problem cases not readily explained by existing theories. We have found another case that seems incompatible with simple Mendelian inheritance in the ABO blood group system. A B O blood group antigens are thought to be transmitted according to Mendelian law. Rernstein [ 3 ] formulated his threeallele theory in 1924, which was later expanded to include allelic subgroups of A and B. This has generally been considered valid, however, it does not explain certain cases observed since then. Several families have been reported [5, 14-16, 181 with A and B antigens transmitted by the same chromosome (cis-AB). Borrtcher [4] offered an explanation for
this unexpected finding by proposing that the A B O blood group antigens are coded by a complex locus in which crossing-over can occur between the A and B subunits. Weiner et al. [20] found another exception to simple Mendelian inheritance, suggesting that modifying genes can affect the expression of the A antigen. The additional fact that group 0 as well as A,B parents have had group A, children [2, 6-8, 13, 171 shows that we do not yet fully understand how the A B O antigens are determined.
Case Report The propositus is a full-term male infant born to a 27-year-old group AB Rho (D) negative Caucasian mother after an uneventful pregnancy. Immediately after delivery, footprints and a picture
A G r o u p 0 Child froni a G r o u p A,B Mother
of the infant were taken together with the mother's fingerprints. A cord blood sample was sent to the blood bank and typed as group 0. A blood sample obtained froni the mother before delivery was typed as group A,B. Since these results appeared to reveal a discrepancy, identification of both mother and infant was carefully checked and new specimens were studied. They confirmed the original results.
Materials and Methods Blood samples were collected from the propositus (111-2) his parents (11-3 and 11-4), his maternal grandparents (1-1 and 1-2) and some of the other family members (11-1, 11-2, 11-6, 11-8 and 111-1) (fig. I). Saliva was obtained f r o m the parents (11-3 and 11-4) and f r o m the infant o n three occasions (when I week old. 3 months and 1 year later). T h e red cells of the propositus, his parents and other family members were typed a s tube tests with commercial antisera, according to standard procedures ( I ) for antigens in the following systems: ABO, MNSs, Kh, Lewis, Kell, Duffy and I. The red cells of the propositus were also tested with anti-H antibodies from three sources ( U l e x ertropcreus lectin, Bombay (O,,) serum and eel serum) and with anti-A,B sera (eleven random group 0 sera). These reactions were read after 30-min incubation times both at room temperature and at 4 "C. Absorption and elution tests (Landsteiner and Miller's heat elution method) were carried out o n the propositus' red cells with normal group 0 cells as the control. Additional studies were made after treating these cells with commercial ficin following the manufacturer's directions. T h e eluates were examined against conimercial group A,, A, and B cells and the infant's own cells. T h e infant was studied this way twice, when he was 3 months old and again 9 months later. His mother's (11-4) red cells were tested for the strength of their A and B antigens. Serial twofold dilutions of commercial anti-A and anti-B antisera were prepared. One drop of a 2% saline suspension of red cells was added t o o n e d r o p of each dilution of antisera. T h e tubes were centri-
177
fuged in a Clay-Adams Serofuge at 3,500rpm f o r 15 sec and the reactions graded a n d scored following procedures recommended by the American Association of Blood Banks 111. T w o group A,B, two A,B, three A,, o n e A, and three B samples were used as controls. Reverse grouping was done using commercial group A,, A,, B and 0 cells following the manufacturer's directions. When the infant was 1 year old, his alloagglutinins were titrated. Serial twofold dilutions of his serum were tested against 5% saline suspensions of group A, o r B cells, o n e d r o p of diluted serum t o o n e d r o p of cell suspension. T h e reactions were read a n d graded after room temperature incubation f o r 30 min and subsequent centrifugation a t 3,500 rpm. T h e reciprocal of the dilution resulting in a 1t macroscopic reaction was considered the titer. Saliva from the propositus a n d f r o m his parents was tested f o r secretion of A, B and H substances by standard hemagglutination inhibition methods [ I , 111 using commercial group A,, B a n d 0 cells as indicators. When the infant was 3 months old, D r . G . F . Springer and Ms. H . Tegttiieyer tested his saliva for secretion of A, B a n d H substances a n d titrated the H substance by standard hemagglutination inhibition assays a s used in their laboratory [19].
Results Figure 1 shows the pedigree and ABO blood groups of the family members tested. The untreated red cells of the propositus did not react with anti-A, anti-B or antiA,B sera. Similar results were obtained with ficin-treated cells. After absorption and elution, no anti-A or anti-B activity was noted in the eluates. His cells did react weakly at birth with both Ulex lectin and 0,, serum, but a similar weak reaction was observed in four out of the ten group 0 cord cells used as controls. By the time the infant was 1 year old, his red cells reacted strongly (4+) with both the lectin and the 0,,serum.
Valdes/Zoes/Froker
178
Table I. The reactions of anti-A and anti-B sera with the red cells of the propositus, his parents and controls Anti-A titer Propositus 111-2 Father 11-3 Mother 11-4 Controls A' A' A' A, A,B A,B A,B A 8 B B B
II
score
0
0
128 128
73 64
128 256 64 32 128 128 32 32
66 71 61 54 68 66 40 39
0 0 0
0 0 0
1
I
Anti-B
-
A
T
titer
score
0 0
0 0
32
55
0 0 0 0
0 0 0 0
128 64 128 256 64 128 128
61 52 62 69 63 64 66
B
4 T L
1-A,E
Z-A,B
3-A,
L-A,B
5-nt
6-A2B
f Fig. 1. Family tree with the ABO blood groups. NT = Not tested.
The infant's serum had no demonstrable alloagglutinins either at birth or at 3 months of age. However, when he was 1 year old, his serum reacted with group A,, A, and B cells but not with 0 cells. His anti-A titer against group A, cells was 16 and his anti-B titer was 1 at room temperature.
Dr. G. F . Springer and Ms. H. Tegtmeyer found that the saliva of the propositus at 16-fold dilution inhibited the agglutination of group 0 cells by anti-H eel serum, but it did not inhibit the agglutination of group A,, A, or B cells by the corresponding antisera. The propositus can be considered to be blood group 0. He was typed as group 0, DCce (R,r), MsMS, Fy(a-b+), Le(a-b+), K-k+. He was found to secrete H substance in his saliva, but not A or B. The infant's mother (11-4) was typed as group A,B, dce (rr), MSMs, Fy(a+b+), Le(a-b+), K-k+. Her red cells reacted well with anti-A serum and less with anti-B serum than the controls (table I ) but not with anti-A, (Dolichos biflorus) commercial lectin. They were not tested with naturally occurring anti-A, or anti-A serum absorbed with group A, cells. Her serum did not react with group A, or B cells. She was found to secrete A, B and H substances in her saliva. The infant's father (11-3) was typed as group A,, DCc Ee (R,R2), MSMs, Fy(a+b+), Le(a-b+), K-k+. He secreted A and H substances in his saliva.
Discussion The Mendelian inheritance of the ABO blood group system is so firmly established that the first concern of the blood bank in this case was to check the identification of both mother and infant. This was easily verified since no other infant had been born within a 5-hour period. After identification was certain, several possible explanations for the anomaly were examined. The infant is not of the O,, phenotype because his red cells react with Ulex anti-H
A Group 0 Child from a Group A,B Mother
lectin, anti-H eel serum and an 0,,serum, and he secretes H substance in his saliva. We considered that the infant could have been an extremely weak subgroup of A or B. There are reports [6-8, 171 of group A,B parents having group A, children. But all the weak subgroups of A listed by Issitt and Issitt [ l l ] do absorb at least some anti-A antibodies. We assume weak subgroups of B act in a similar way although these are much less frequent and not so well known. The infant also lacked other hallmarks of weak subgroups, like weak A or B substances in his saliva or missing alloagglutinins. At the age of 1 year, he had anti-A and anti-B agglutinins in his serum in titers comparable with results reported by Fong et al. [9] and Springer and Horton [19] for children of similar age. During the preparation of this report, the mother had a second child who was also group 0. This eliminated two previously considered explanations for the infant’s absence of A and B antigens: (a) a genetic cross-over occurring in the mother’s germinal cells and (b) a mutant gene coding in the infant for an abnormal transferase. The probability of either happening twice at a precise locus in the same family is essentially zero. Another possibility is a weak A or B gene that is completely suppressed by some other mechanism, such as a modifying gene. While a recessive gene can be considered, it is pertinent to point out that the parents of the propositus are in no way related. Beckers et al. [2] and van Loghem and van der Hart [I31 refer to cases of demonstrated A, antigen (probably A,) occurring in the offspring of group 0 parents. Any future offspring of the propositus will probably add interesting information to this case.
179
The most likely explanation is that the mother carries both A and B genes on the same chromosome. We were able to test only some of the family members and the results neither support nor rule out this possibility (fig. 1). However, if this is the case, the A and B antigens of the family have different characteristics from the well-documented cases we found in the literature [5, 14, 15, 181. All of them, as well as the Japanese families referred to by Race and Sanger [16], have weak B antigens and some anti-B activity in their sera, which is not the case with this infant’s mother. Although we did not test the strength of the A and B antigens of the other members of the family, their red cells reacted strongly with commercial anti-A and anti-B sera and they showed no anti-B activity in their sera. A similar case of a group A,B mother who had a group 0 child was reported by Haselhorst and Lauer [lo] in 1931. They also refer to an unpublished case of a group A,B father with an 0 child. Kossovifch [12] in 1929 reported 2 cases, a group AB mother and a group AB father, each with a group 0 child. However, no serological data were included. In our case, transferase studies would be essential to investigate the possibility of a cis AB or a recessive suppressor gene. Unhappily, the family is no longer available for further testing.
Acknowledgements The authors wish to thank Dr. G e o r g F. Springer and Ms. Herta Tegtmeyer for the absorption and elution studies and the testing of the saliva. Dr. Springer kindly reviewed the manuscript and offered helpful advice. We also thank the Rosurio and Kiel families for their cooperation, Dr. Hartmann Friederici and
Valdes/Zoes/Fro ker
180
Dr. Nenzahrr Sliuron for encouragement and the review of the manuscript; Dr. Volkcr Duhe for allowing us the use of the facilities of the Evanston Hospital Blood Bank; Ms. Phyllis Unger from the Michael Reese Hospital Blood Bank for the serum of the Bombay donor and Ms. Wnlrraud Leif for expert secretarial assistance.
References 1 American Association of Blood Banks: Technical methods and procedures; 6th ed. (Am. Ass.
of Blood Banks, Chicago 1974). 2 Beckers, T.; Loghem, J. J., jr. van, and Dunsford, I.: A second example of the weak antigen A, occurring in the offspring of group 0 parents. Vox Sang. 5: 145-147 (1955). 3 Bernstein, F.: Ergebnisse einer biostatistischen zusammenfassenden Bctrachtung iiber die erblichen Blutstrukturen des Menschen. Klin. Wschr. 3: 1495-1497 (1924). 4 Boettcher, B . : Modification of Bernstein’s multiple allele theory for the inheritance of the ABO blood groups in the light of modern genetical concepts. Vox Sang. I ] : 129-136 (1966). 5 Busch, M. and Sabo, B.: Three generations of AB antigens in cis position. Abstract. Transfusion 13: 362 (1973). 6 Cahan, A,; Jack, J.A.; Scuder, J.; Sargent, M.; Sanger, K., and Race, R. R.: A family in which Ax is transmitted through a person of the hlood group A,B. Vox Sang. 2: 8-15 (1957). 7 Ducos, J.; Marty, Y.,and Ruffie, J.: A case of Ax phenotype transmitted by an A,B parent. Vox Sang. 29: 390-393 (1975). 8 Fischer, N. and Cahan, A,: An addition to the family in which Ax is transmitted through a person of the blood group A,B. Vox Sang. 7: 484 ( I 962). 9 Fong, S. W.; Qaqundah, B. Y., and Taylor, S. F.: Developmental patterns of ABO isoagglutinins in normal children correlated with the effects of age, sex and maternal isoagglutinins. Transfusion 14: 551-559 (1974).
10 Haselhorst, G. und Lauer, A.: Zur Blutgruppenkombination Mutter AB-Kind 0. Z. Konstit. Lehre 16: 227-230 (1931). 1 1 Issitt, P. D. and Issitt, 0. H.: Applied blood group serology; 2nd ed. (Spectra Biologicals, Oxnard 1975). 12 Kossovitch, N.: Les groupes sanguins chez les FranCais ct les rigles de I’hCrCditC. Revue Anthrop. 39: 374-379 (1929). 13 Loghem, J . J . van and Hart, M. van der: The weak antigen A, occurring in the offspring of group 0 parents. Vox Sang. 4: 69-75 (1954). 14 Madsen, G. and Heisto, H.: A Korean family showing inheritance of A and B on the same chromosome. Vox Sang. 14: 211-217 (1968). 15 Pacuszka. T.; KoScielak, J.; Seyfried, H., and Walewska, I.: Biochemical, serological and family studies in individuals with cis-AB phenotypes. Vox Sang. 29: 292-300 (1975). 16 Race, R . R . and Sanger, R.: Blood groups in man; 6th ed. (Blackwell, Oxford 1975). 17 Salmon, C.; Salmon, E. et Rcviron, J.: Etude immunologique et gCnCtique de la variabilite du phknotype Ax. Nouv. Revue fr. HCmat. 5: 275-290 (1965). 18 Seyfried, H., Walewska, I. and Werblinska, B.: Unusual inheritance of ABO groups in a family with weak B antigens. Vox Sang. 9: 268-277 (1964). 19 Springer, G . F. and Horton, R. E.: Blood group isoantibody stimulation in man by feeding blood group-active bacteria. J. clin. Invest. 48. 1280-1291 (1969). 20 Weiner, W.; Lewis, H. B. M.; Moores, P.; Sanger, R., and Race, R. K.: A gene, y, modifying the blood group antigen A. Vox Sang. 2: 2537 (1957).
Received: April 5, 1977 Accepted: October 15, 1977 Maria Dolores Valdes Servizio de Hematologia Ciudad Sanitaria. l o de Octubre Carretera de Andalucia Madrid (Spain)
Unusual Inheritance in the ABO Blood Group System: A Group 0 Child from A Group A2B Mother Maria Dolores Valdes, Caroline Zoes and Alice Froker Department o f Pathology and Laboratory Medicine, Evanston Hospital, Evanston, 111.
Abstract. A serologically typical group A2B mother with no unusual anti-A or anti-B agglutinins delivered a normal group 0 infant with no demonstrable A or B antigens. By the age of 1 year the child had developed anti-A and anti-B agglutinins. He had H antigen and secreted H substance in his saliva. A second groupochild has since been born. Although family studies were inconclusive, the most likely explanation is that the mother is a ci.v-AB. If this is the case, she differs from other reported cis-ABs in her apparently normal B antigen and the lack of anti-B antibodies in her serum.
Concepts of genetic mechanisms have evolved partly by systematic research and partly by study of problem cases not readily explained by existing theories. We have found another case that seems incompatible with simple Mendelian inheritance in the ABO blood group system. A B O blood group antigens are thought to be transmitted according to Mendelian law. Rernstein [ 3 ] formulated his threeallele theory in 1924, which was later expanded to include allelic subgroups of A and B. This has generally been considered valid, however, it does not explain certain cases observed since then. Several families have been reported [5, 14-16, 181 with A and B antigens transmitted by the same chromosome (cis-AB). Borrtcher [4] offered an explanation for
this unexpected finding by proposing that the A B O blood group antigens are coded by a complex locus in which crossing-over can occur between the A and B subunits. Weiner et al. [20] found another exception to simple Mendelian inheritance, suggesting that modifying genes can affect the expression of the A antigen. The additional fact that group 0 as well as A,B parents have had group A, children [2, 6-8, 13, 171 shows that we do not yet fully understand how the A B O antigens are determined.
Case Report The propositus is a full-term male infant born to a 27-year-old group AB Rho (D) negative Caucasian mother after an uneventful pregnancy. Immediately after delivery, footprints and a picture
A G r o u p 0 Child froni a G r o u p A,B Mother
of the infant were taken together with the mother's fingerprints. A cord blood sample was sent to the blood bank and typed as group 0. A blood sample obtained froni the mother before delivery was typed as group A,B. Since these results appeared to reveal a discrepancy, identification of both mother and infant was carefully checked and new specimens were studied. They confirmed the original results.
Materials and Methods Blood samples were collected from the propositus (111-2) his parents (11-3 and 11-4), his maternal grandparents (1-1 and 1-2) and some of the other family members (11-1, 11-2, 11-6, 11-8 and 111-1) (fig. I). Saliva was obtained f r o m the parents (11-3 and 11-4) and f r o m the infant o n three occasions (when I week old. 3 months and 1 year later). T h e red cells of the propositus, his parents and other family members were typed a s tube tests with commercial antisera, according to standard procedures ( I ) for antigens in the following systems: ABO, MNSs, Kh, Lewis, Kell, Duffy and I. The red cells of the propositus were also tested with anti-H antibodies from three sources ( U l e x ertropcreus lectin, Bombay (O,,) serum and eel serum) and with anti-A,B sera (eleven random group 0 sera). These reactions were read after 30-min incubation times both at room temperature and at 4 "C. Absorption and elution tests (Landsteiner and Miller's heat elution method) were carried out o n the propositus' red cells with normal group 0 cells as the control. Additional studies were made after treating these cells with commercial ficin following the manufacturer's directions. T h e eluates were examined against conimercial group A,, A, and B cells and the infant's own cells. T h e infant was studied this way twice, when he was 3 months old and again 9 months later. His mother's (11-4) red cells were tested for the strength of their A and B antigens. Serial twofold dilutions of commercial anti-A and anti-B antisera were prepared. One drop of a 2% saline suspension of red cells was added t o o n e d r o p of each dilution of antisera. T h e tubes were centri-
177
fuged in a Clay-Adams Serofuge at 3,500rpm f o r 15 sec and the reactions graded a n d scored following procedures recommended by the American Association of Blood Banks 111. T w o group A,B, two A,B, three A,, o n e A, and three B samples were used as controls. Reverse grouping was done using commercial group A,, A,, B and 0 cells following the manufacturer's directions. When the infant was 1 year old, his alloagglutinins were titrated. Serial twofold dilutions of his serum were tested against 5% saline suspensions of group A, o r B cells, o n e d r o p of diluted serum t o o n e d r o p of cell suspension. T h e reactions were read a n d graded after room temperature incubation f o r 30 min and subsequent centrifugation a t 3,500 rpm. T h e reciprocal of the dilution resulting in a 1t macroscopic reaction was considered the titer. Saliva from the propositus a n d f r o m his parents was tested f o r secretion of A, B and H substances by standard hemagglutination inhibition methods [ I , 111 using commercial group A,, B a n d 0 cells as indicators. When the infant was 3 months old, D r . G . F . Springer and Ms. H . Tegttiieyer tested his saliva for secretion of A, B a n d H substances a n d titrated the H substance by standard hemagglutination inhibition assays a s used in their laboratory [19].
Results Figure 1 shows the pedigree and ABO blood groups of the family members tested. The untreated red cells of the propositus did not react with anti-A, anti-B or antiA,B sera. Similar results were obtained with ficin-treated cells. After absorption and elution, no anti-A or anti-B activity was noted in the eluates. His cells did react weakly at birth with both Ulex lectin and 0,, serum, but a similar weak reaction was observed in four out of the ten group 0 cord cells used as controls. By the time the infant was 1 year old, his red cells reacted strongly (4+) with both the lectin and the 0,,serum.
Valdes/Zoes/Froker
178
Table I. The reactions of anti-A and anti-B sera with the red cells of the propositus, his parents and controls Anti-A titer Propositus 111-2 Father 11-3 Mother 11-4 Controls A' A' A' A, A,B A,B A,B A 8 B B B
II
score
0
0
128 128
73 64
128 256 64 32 128 128 32 32
66 71 61 54 68 66 40 39
0 0 0
0 0 0
1
I
Anti-B
-
A
T
titer
score
0 0
0 0
32
55
0 0 0 0
0 0 0 0
128 64 128 256 64 128 128
61 52 62 69 63 64 66
B
4 T L
1-A,E
Z-A,B
3-A,
L-A,B
5-nt
6-A2B
f Fig. 1. Family tree with the ABO blood groups. NT = Not tested.
The infant's serum had no demonstrable alloagglutinins either at birth or at 3 months of age. However, when he was 1 year old, his serum reacted with group A,, A, and B cells but not with 0 cells. His anti-A titer against group A, cells was 16 and his anti-B titer was 1 at room temperature.
Dr. G. F . Springer and Ms. H. Tegtmeyer found that the saliva of the propositus at 16-fold dilution inhibited the agglutination of group 0 cells by anti-H eel serum, but it did not inhibit the agglutination of group A,, A, or B cells by the corresponding antisera. The propositus can be considered to be blood group 0. He was typed as group 0, DCce (R,r), MsMS, Fy(a-b+), Le(a-b+), K-k+. He was found to secrete H substance in his saliva, but not A or B. The infant's mother (11-4) was typed as group A,B, dce (rr), MSMs, Fy(a+b+), Le(a-b+), K-k+. Her red cells reacted well with anti-A serum and less with anti-B serum than the controls (table I ) but not with anti-A, (Dolichos biflorus) commercial lectin. They were not tested with naturally occurring anti-A, or anti-A serum absorbed with group A, cells. Her serum did not react with group A, or B cells. She was found to secrete A, B and H substances in her saliva. The infant's father (11-3) was typed as group A,, DCc Ee (R,R2), MSMs, Fy(a+b+), Le(a-b+), K-k+. He secreted A and H substances in his saliva.
Discussion The Mendelian inheritance of the ABO blood group system is so firmly established that the first concern of the blood bank in this case was to check the identification of both mother and infant. This was easily verified since no other infant had been born within a 5-hour period. After identification was certain, several possible explanations for the anomaly were examined. The infant is not of the O,, phenotype because his red cells react with Ulex anti-H
A Group 0 Child from a Group A,B Mother
lectin, anti-H eel serum and an 0,,serum, and he secretes H substance in his saliva. We considered that the infant could have been an extremely weak subgroup of A or B. There are reports [6-8, 171 of group A,B parents having group A, children. But all the weak subgroups of A listed by Issitt and Issitt [ l l ] do absorb at least some anti-A antibodies. We assume weak subgroups of B act in a similar way although these are much less frequent and not so well known. The infant also lacked other hallmarks of weak subgroups, like weak A or B substances in his saliva or missing alloagglutinins. At the age of 1 year, he had anti-A and anti-B agglutinins in his serum in titers comparable with results reported by Fong et al. [9] and Springer and Horton [19] for children of similar age. During the preparation of this report, the mother had a second child who was also group 0. This eliminated two previously considered explanations for the infant’s absence of A and B antigens: (a) a genetic cross-over occurring in the mother’s germinal cells and (b) a mutant gene coding in the infant for an abnormal transferase. The probability of either happening twice at a precise locus in the same family is essentially zero. Another possibility is a weak A or B gene that is completely suppressed by some other mechanism, such as a modifying gene. While a recessive gene can be considered, it is pertinent to point out that the parents of the propositus are in no way related. Beckers et al. [2] and van Loghem and van der Hart [I31 refer to cases of demonstrated A, antigen (probably A,) occurring in the offspring of group 0 parents. Any future offspring of the propositus will probably add interesting information to this case.
179
The most likely explanation is that the mother carries both A and B genes on the same chromosome. We were able to test only some of the family members and the results neither support nor rule out this possibility (fig. 1). However, if this is the case, the A and B antigens of the family have different characteristics from the well-documented cases we found in the literature [5, 14, 15, 181. All of them, as well as the Japanese families referred to by Race and Sanger [16], have weak B antigens and some anti-B activity in their sera, which is not the case with this infant’s mother. Although we did not test the strength of the A and B antigens of the other members of the family, their red cells reacted strongly with commercial anti-A and anti-B sera and they showed no anti-B activity in their sera. A similar case of a group A,B mother who had a group 0 child was reported by Haselhorst and Lauer [lo] in 1931. They also refer to an unpublished case of a group A,B father with an 0 child. Kossovifch [12] in 1929 reported 2 cases, a group AB mother and a group AB father, each with a group 0 child. However, no serological data were included. In our case, transferase studies would be essential to investigate the possibility of a cis AB or a recessive suppressor gene. Unhappily, the family is no longer available for further testing.
Acknowledgements The authors wish to thank Dr. G e o r g F. Springer and Ms. Herta Tegtmeyer for the absorption and elution studies and the testing of the saliva. Dr. Springer kindly reviewed the manuscript and offered helpful advice. We also thank the Rosurio and Kiel families for their cooperation, Dr. Hartmann Friederici and
Valdes/Zoes/Fro ker
180
Dr. Nenzahrr Sliuron for encouragement and the review of the manuscript; Dr. Volkcr Duhe for allowing us the use of the facilities of the Evanston Hospital Blood Bank; Ms. Phyllis Unger from the Michael Reese Hospital Blood Bank for the serum of the Bombay donor and Ms. Wnlrraud Leif for expert secretarial assistance.
References 1 American Association of Blood Banks: Technical methods and procedures; 6th ed. (Am. Ass.
of Blood Banks, Chicago 1974). 2 Beckers, T.; Loghem, J. J., jr. van, and Dunsford, I.: A second example of the weak antigen A, occurring in the offspring of group 0 parents. Vox Sang. 5: 145-147 (1955). 3 Bernstein, F.: Ergebnisse einer biostatistischen zusammenfassenden Bctrachtung iiber die erblichen Blutstrukturen des Menschen. Klin. Wschr. 3: 1495-1497 (1924). 4 Boettcher, B . : Modification of Bernstein’s multiple allele theory for the inheritance of the ABO blood groups in the light of modern genetical concepts. Vox Sang. I ] : 129-136 (1966). 5 Busch, M. and Sabo, B.: Three generations of AB antigens in cis position. Abstract. Transfusion 13: 362 (1973). 6 Cahan, A,; Jack, J.A.; Scuder, J.; Sargent, M.; Sanger, K., and Race, R. R.: A family in which Ax is transmitted through a person of the hlood group A,B. Vox Sang. 2: 8-15 (1957). 7 Ducos, J.; Marty, Y.,and Ruffie, J.: A case of Ax phenotype transmitted by an A,B parent. Vox Sang. 29: 390-393 (1975). 8 Fischer, N. and Cahan, A,: An addition to the family in which Ax is transmitted through a person of the blood group A,B. Vox Sang. 7: 484 ( I 962). 9 Fong, S. W.; Qaqundah, B. Y., and Taylor, S. F.: Developmental patterns of ABO isoagglutinins in normal children correlated with the effects of age, sex and maternal isoagglutinins. Transfusion 14: 551-559 (1974).
10 Haselhorst, G. und Lauer, A.: Zur Blutgruppenkombination Mutter AB-Kind 0. Z. Konstit. Lehre 16: 227-230 (1931). 1 1 Issitt, P. D. and Issitt, 0. H.: Applied blood group serology; 2nd ed. (Spectra Biologicals, Oxnard 1975). 12 Kossovitch, N.: Les groupes sanguins chez les FranCais ct les rigles de I’hCrCditC. Revue Anthrop. 39: 374-379 (1929). 13 Loghem, J . J . van and Hart, M. van der: The weak antigen A, occurring in the offspring of group 0 parents. Vox Sang. 4: 69-75 (1954). 14 Madsen, G. and Heisto, H.: A Korean family showing inheritance of A and B on the same chromosome. Vox Sang. 14: 211-217 (1968). 15 Pacuszka. T.; KoScielak, J.; Seyfried, H., and Walewska, I.: Biochemical, serological and family studies in individuals with cis-AB phenotypes. Vox Sang. 29: 292-300 (1975). 16 Race, R . R . and Sanger, R.: Blood groups in man; 6th ed. (Blackwell, Oxford 1975). 17 Salmon, C.; Salmon, E. et Rcviron, J.: Etude immunologique et gCnCtique de la variabilite du phknotype Ax. Nouv. Revue fr. HCmat. 5: 275-290 (1965). 18 Seyfried, H., Walewska, I. and Werblinska, B.: Unusual inheritance of ABO groups in a family with weak B antigens. Vox Sang. 9: 268-277 (1964). 19 Springer, G . F. and Horton, R. E.: Blood group isoantibody stimulation in man by feeding blood group-active bacteria. J. clin. Invest. 48. 1280-1291 (1969). 20 Weiner, W.; Lewis, H. B. M.; Moores, P.; Sanger, R., and Race, R. K.: A gene, y, modifying the blood group antigen A. Vox Sang. 2: 2537 (1957).
Received: April 5, 1977 Accepted: October 15, 1977 Maria Dolores Valdes Servizio de Hematologia Ciudad Sanitaria. l o de Octubre Carretera de Andalucia Madrid (Spain)
