4 ) FROM STATE INSTIZUTE OF PUBLIC HEALTH, OSLO. 2 ) MINISTRY OF HEALTH, BLOOD GROUP REFERENCE LABORATORY,

LISTER INSTITUTE, LONDON. 3 ) MEDICAL RESEARCH COUNCIL BLOOD GROUP RESEARCH U N I T ,

LISTER INSTITUTE, LONDON.

T B E Rh GENOTYPES OF A SERIES OF OSLO BLOOD DONORS

By Ot to Har tmann, A. E . Mourant and R. R . Race. !

(Received for publication April 28th 1947.)

The blood of 226 Oslo Red Cross Transfusion Donors has been tested for agglutination by the six anti-Rh sera, anti-D, anti-C, anti-c, anti-Cw, anti-E and anti-e. The samples were unselected in respect of their Rh groups which had not previously been determined. The results are shewn in Table 1.

Table 4 . The interactions of 226 samples of blood f r o m Oslo donors w i t h

six anti-Rh sera.

Most frequent genotype i n Number Percentage D C c C W E e this reaction group

Anti-

+ + - - - + + + + - - + + + + - + + + - + - + - + - + - + + + - - + + - + - - + - + + - - + + + - + - + + - + + - + + - + + + +

--

34 83 35 5

26 31 1 2 4 2 3

15.04 36.73 15.49 2.21

11.50 13.72

0.44 0.88 1.77 0.88 1.33

CDe/CDe CDe/cde CDe/cDE I

cDE/cDE cDE/cde cde/cde cDe/cde Cde/cde Cw De'CDe CWDe/cde CWDe/cDE

A further thirteen different reaction groups are possible, but of these there were no examples in this series.

33 1

While the results do not differ greatly from the English distribu- tion, the following differences are noticable though not statistically significant. There is a shortage of cDe/cde (Rzr). In England this group has a frequency of 2.1 per cent. There is an excess of bloods containing Cw. Of 226 English people 5.7 would be expected to have Cw ; 9 of the Oslo samples possessed it.

Since the completion of the work reported in this paper, we have pad the opportunity of testing samples of blood from other parts of the mainland of Europe. Samples from Latvia, Germany and Czecho- Slovakia, like those from Oslo, shew a frequency of the Cw antigen greater than that found in England. Statistically, the difference is highly significant when the pooled mainland figures are compared with those for England.

Two chromosomes are responsible for an Rh blood group; each one carries three genes, chosen from the following alternatives: C or c or Cw, and D or d, and E or e. For example, the Rh chromosome in an ovum might carry CDe, and the sperm that fertilized it might carry the chromosome cde. The zygote would then be of the genotype CDdcde. As the three genes are tightly linked they keep together, and the sex cells produced by the zygote in its turn will be of two parental types CDe and cde.

A person thus has 6 Rh genes, which may be of as few as three kinds as in the homozygote CDdCDe, or all six may be different as in the triple heterozygote CDe/cdE. Each gene produces its equivalent antigen on the red cell, and each antigen is capable of inducing a cor- responding antibody. The frequency with which the various antigens succeed in stimulating their equivalent antibodies varies considerably. The order of antigenic success seems to be D C E c C" e d.

The discovery by Fisheri) of the allelomorphisms of Cc, Dd, Ee, was fundamental to our understanding of what was previously a be- wildering and apparently arbitrary interaction of antigens and anti- bodies. The allelomorphic nature of these antigens is now proved beyond doubt, although the exact genetic mechanism is still a matter of argument. Fisher's original suggestion of three tightly linked genes, for which there is some evidencg), is more satisfactory than the alter- native possibility of a single locus with 3 allelomorphic subgenes.

The last column in Table I is headed >>most frequent genotype in the reaction group<<. As an example of what this means, consider the second row. There were 83 bloods giving the reaction +++ -- +, and these might be CDdcde or CDe/cDe or cDe/Cde, for they all give the same reactions. If an anti-d serum had been available the middle genotype would have been separated from the first and last. Among the 83 there may be some persons of all three types, but in the case of any one individual we guess that such blood is CDe/cde, because we know that the chromosomes CDe and cde are very common ones, whereas Cde and cDe are rarer ones, in the English and Norwegian

332

population. For example, in England the chromosome frequencies arc : CDe 40.71 per cent, cde 39.80 per cent, Cde 1.15 per cent and cDe 2.16 per cent.

From the observed frequencies in the reaction groups, the fre- quencies of the chromosomes can be calculated by a simple method for which we are indebted to Professor R. A. Fisher3). These frequen- cies for the Oslo group are given in Table 2.

Table 2. R h chromosome f requenc ies .

England 1 (226 :::pies) 1 (1073 samples*)

CDe cde cDE C WDe Cde cDe cdE CDE

38.01 per cent 37.04 - 21.37 -

1.82 - 1.18 - 0.59 -

not observed not observed

40.71 per cent 39.80 - 13.67 - 1.26 - 1.15 - 2.16 - 0.81 - 0.44 -

These chromosome frequencies can be used to calculate the ex- pected number of bloods in certain reaction groups and afford a chcclc on the reliability of the technique. As an example, the frequency of the genotype CDeIcde = 38.01 % X 37.04 % X 2 = 28.16 %.

Table 3. T h e chromosomes , r ecombined acco id ing to the ir ca lcula ted f requenc ies , givin,g

the expected d i s t r ibu t ion o f Os lo bloods in cer ta in geno type groups . ~ ~~ ~~

Anti- Absolute numbers Expected per cent

D C c C W E e Exnected 1 Observed

+ + + - - + CDe/cde 28.16

CDe/cDe 0.45

cDE/Cde 0.50 }

cDe/Cde 0.01 } 28.62 64.68 83

+ + + - + + CDe/cDE 16.25 i6.75 37.86 35

+ - + - + + cDE/cde 15.83 cDe/cDE 0.25 } 16*08 36.34 33

It will be seen that the expected and observed numbers in two of

The discrepancy in the first group in Table 3 is highly significant these groups do not fit a t all well.

statistically and in the third group just short of significance.

These discrepancies throw doubt on the reliability of the technique of testing and possible causes must be considered. (1) The antisera; these antisera were being used to test a much larger series of English bloods at the same time as the testing of the Oslo bloods. The English series fitted the expected distribution with quite remarkable accuracy. The antisera must be considered beyond reproach.

( 2 ) The red cells; owing to their having undergone a journey the condition of the red cells is open to question. The blood was tested within 4 days of being taken. It was in the form of 10 C.C. of whole blood in a dry sterile tube. It had been refrigerated for 1 day of its journey. If any samples of blood looked a t all lysed, they were dis- carded before the tests were begun. The interactions were satisfactory and we believe them to be correct. We are therefore forced to conclude that the disturbance of distribution is one due to chance and that the figures should not be suppressed for this reason.

It seems reasonable to suppose from these rather disappointing figures that the Rh chromosome frequencies of blood donors in Oslo are much the same as those in England.

Summary. Blood from 226 Oslo donors has been tested with the six Rh anti-

sera, anti-D-C-c-CW-E & -e. A s far as can be judged from this small series, it seems that the chromosome frequencies do not differ very much from those found in England.

R II F E R E N CE S 1. F i s l i e ~ , R . A. cited by Race, R . H . (1944): An ))incompletecc antibody in

human serum. Nature, London, !53, 771. 2. Fisher, R . A . and Race, H . R . (1946): R h gene frequencies in Britain. Nature,

London, i57, 48. 3. Race, R . R. , Mourant, A. E. and Marjory N . fifcFurlan,e (1946): Travaux

recents sur les antigenes et anticorps Rh; itvec une Btude parti- culiere de la theorie de Fisher. Revue d'Hematologie, !, 9.

4. Snnger, R, , Lawler , S . D., Roce. R . R., and Mourant, A. E.: Blood, The Journal of Hematology; in press.