ABH secretion and natural selection.

The secretor gene, which determines secretion of the ABH blood group antigens into saliva and other fluids, has widely varying frequencies in different healthy populations. Its frequency in patients suffering from certain diseases also differs from that in healthy persons. These observations suggest that frequencies of the gene are to some extent the results of natural selection. One means of selection is through haemolytic disease of the newborn. Women, mostly of group O, become immunized to the A or B antigen of a fetus, and this or subsequent fetuses are at risk from haemolytic disease of the newborn. Affected fetuses are preponderantly secretors; this is probably a genetic consequence of all or most immunizing fetuses being secretors. Selection against the secretor factor as well as against blood groups A and B is thus liable to occur. Similar processes of selection seem to operate through fetal loss by early abortion. It is suggested that counter-selection favouring secretors may result from certain epidemic infectious diseases.

The blood groups and other hereditary blood factors of the Icelanders.

Bjarnason, Bjarnason, Edwards, Fridriksson, Magnusson, Mourant and Tills (1973) published preliminary data on a study of Iceland. The present paper gives the complete data of the study and extends the sample size for most of the genetic systems to over 1500 individuals, approximately 1/130 of the population. The sample was divided into seven subpopulations and these were compared using a genetic distance matrix. Considerable internal variation was revealed with two groups appearing very different. The seven regions were then compared with possible founding populations and no close relationships were found. The possible mechanism for the internal variation and the differences between Icelandic gene frequencies and those from other N.W. European populations are discussed.

Red cell antigen, serum protein and red cell enzyme polymorphisms in Eastern Highlanders of New Guinea.

A series of 1,187 blood samples from eight population groups in the Eastern Highlands of Papua New Guinea were tested for genetic variation in blood groups, serum proteins and red cell enzyme systems. The populations belonged to the language groups Gahuku-Asarc-Bena Bena, Kamano, Yagaria, Keiagana, Fore, Agarabe, Auyana and Tairora. Polymorphic variation was found in the ABO, MNS, P1, Rh, Hp, Tf, SEP, 6-PGD, ADA, MDH, and PGM genetic systems. East to West variation was shown in the language groups; the O, S, R2, and R0 genes increase in frequency from East to West and the A, R1, and M genes decrease in the same direction. In the East higher frequencies were found for the Du antigen, for the PGM21 gene and for a PGM second locus variant. The MDH 3 variant was found in all the populations, its highest value being in the Tairora.

Red cell antigen, serum protein and red cell enzyme polymorphisms in Karkar Islanders and inhabitants of the adjacent North Coast of New Guinea.

Blood samples from the Waskia and Takia populations of Karkar Island, Papua New Guinea, and other nearby mainland populations, were tested for genetic variation in blood group, serum protein and red cell enzyme systems. Polymorphic variation was present in the ABO, P, MNS, Rh, Lewis, Duffy, Kidd and Gerbich blood group systems, in the Hp and Tf serum protein systems, and in the acid phosphatase, 6-PGD, ADA, PGM, MDH, and G-6-PD enzyme systems. A small number of variants was found in other systems: there were 4 Lu(a+), 1 Kp(a+), 2 C variants in the acid phosphatase system, 6 LDH variants, 1 ADA3-1 and 1 AK2-1 sample. All samples were negative for the red cell antigens Cw, Vw, He, K, Jsa, Dia, Wra, Rd and Marriott, and no variation was observed in the PHI enzyme system. The results are discussed in relation to those obtained on other Papua New Guinea populations.

Blood group, protein, and red cell enzyme polymorphisms of the Hadza of Tanzania.

Three subpopulations of the Hadza were examined for the following antigens and proteins including enzymes A1ABH, MNS Henshaw, CcCwDDuEeVCe, Lua, KJsa, Fy1Fy2, JkaJkb, Dia, Wra, haemoglobin, haptoglobin, transferrin, acid phosphatase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphoglucomutase, adenylate kinase, lactate dehydrogenase, and malate dehydrogenase. The results are discussed in relation to other African populations including the Sandawe, Nyaturu, Pygmies, San, and Khoikhoi.

Genetic studies of the population of the Isle of Man.

A sample of the Isle of Man population was tested for the following red cell antigens, serum proteins and red cell enzymes: ABH; MNSs He; Cc CwD Du Ee Ce; K k Kpa Kpb; Lua; P1; Fya Fyb; haptoglobin; transferrin; Ag; acid phosphatase; phosphoglucomutase; adenylate kinase; esterase D; adenosine deaminase and 6-phosphogluconate dehydrogenase. The study comprised 219 blood donors, 338 secondary school children and 116 females attending the only antenatal clinic. The results were studied for intra-island variation and for their their relationship with other Irish Sea Basin populations. The total sample results were compared with data for England, Cumbria, Eire, Northern Ireland, S.W. Scotland and Wales using a genetic distance measure.

Genetic surveys from the Central, Morobe and Northern Districts, Papua New Guinea.

The results of blood group surveys on a number of linguistic groups inhabiting contiguous areas within the Goilala sub-district of the Central District, the southern part of the Morobe District and the Northern District are reported. Altogether about 1900 subjects were tested, but the extent of testing varied. Red cell enzyme and serum protein systems were also investigated in two groups. Similarities and dissimilarities of blood group distributions are noted, as also are some possible gene gradients among peoples living to the north of the main divide. Two groups, the Kuni/Tauade of the Goilala sub-district, and the Roro/Kovio living towards the Papuan Gulf coast seem well distinguished from the remainder. Genetic distances were calculated for five populations north of the divide, and agree with the geographical and linguistic situation. The Weri people of the middle Waria provided an example of Hp 2-1 modified, two examples of the MDH.NG.1 variant and one of AK 2-1.

Red cell antigen, serum protein, and red cell enzyme polymorphisms in inhabitants of the Jimi Valley, Western Highlands, New Guinea.

A series of blood samples from four villages in the Jimi Valley, Western New Guinea Highlands, has been tested for genetic variation in blood group, serum protein, and red cell enzyme systems. Polymorphic variation was present for the AB0, MNS, P, and Rh blood group systems, for the Hp and Tf serum protein systems, and for the acid phosphatase, 6-PGD, PGM, MDH, and ADA enzyme systems. One each of the following variants was detected: Ge(a-), G6PD deficient, AK 2-1 and PHI 7-1 or 8-1. All samples tested were Cw-, K-, Kp(a-), Wr(a-), Fy(a+ b-), Rd-, and LDH normal. Genetic distance analysis places the Jimi Valley populations closer to peoples of the Chimbu-Chuave and Wahgi-Hagen areas than to the Maring people of the Simbai Valley to the north.

Linkage equilibrium and disequilibrium in human population studies.

It is suggested that in such genetic systems as HLA, characterized by sets of alleles at several closely linked loci, the existence of a state of linkage disequilibrium in a population indicates that this population is the result of recent hybridization between two or more populations, which may previously each have been in a state of equilibrium. Disequilibrium may, however, be modified by natural selection and by genetic drift. Examples of disequilibrium in the Rh, MNSs and HLA systems are discussed.

The inherited blood factors of some Northern Nigerians.

Results are presented on 147 individuals from northern Nigeria who were tested for the red cell antigens A, A1, B, H, M, N, S, s, He, P1, C, D, Du, E, c, e, Ce, v, Lua, Jka (some for Jkb), Lua, K, Jsa (some for Jsb), Kpa, Rd, Fya and Fyb, and for variants of the serum proteins haptoglobin and transferrin and of the red cell enzymes acid phosphatase, phosphoglucomutase, glucose-6-phosphate dehydrogenase, adenylate kinase, adenosine deaminase, phosphohexose isomerase and lactate dehydrogenase. The results found are of interest as they are among the very few published for this area of Nigeria, but they show little that is unexpected for people living in this region.

The blood groups and other heriditary blood factors of Yemenite and Kurdish Jews.

Blood specimens collected fro Yemenite and Kurdish Jews living in Israel were tested for 11 blood group systems 5 plasma protein systems and 9 systems of red-cell enzymes. The results of these tests were combined with those of tests on other Yemenite and Kurdish Jews, reported by Godber et al. (1973), the total data sorted according to the place of origin of the subjects or their parents in the Yemen Arab Republic and Kurdistan respectively. Gene frequencies were calculated for each of the local populations so defined. It is confirmed that the Yemenite Jews show a close relationship to the Yemenite Arabs, but those from the southern part of the Yemen Arab Republic have a higher frequency of African marker genes than those in the north. The Habbanite Jews have a similar rather high frequency of African genes (Bonné et al., 1970). The Kurdish Jews from Iran and northern-western Iraq show a moderate genetic resemblance to the indigenous Kurds of Iran, while those from south-eastern Iraq differ considerably, especially in their low frequency of A1, high B, high CDe (R1) and low cde (r).

Blood groups of the Irish.

Some 1800 blood donors from the Republic of Ireland and Northern Ireland have been tested for the antigens A A1 B H; M N Ss Henshaw; C c Cw D Du E e Ce; Wra; P1; Lua; K k Kpa; Fya Fyb; and Rd (Radin). The results are compared with those already available for Ireland and an attempt is made to interpret them in terms of populations movements. With the exception of the high O frequency in the West, believed to represent the remnants of Mesolithic peoples, the blood groups are very similar to those in the rest of Europe, and show no significant differences between the different provinces in Ireland.

The blood groups, serum groups, red-cell isoenzymes and haemoglobins of the Sandawe and Nyaturu of Tanzania.

Blood specimens from members of the click-speaking Sandawe tribe of Tanzania and of the adjacent Bantu-speaking Nyaturu tribe have been tested for antigens of 11 blood group systems, for variants of 3 plasma-protein systems and 9 red-cell-enzyme systems, for haemoglobin variants. The results are tabulated and gene frequencies computed. For most systems, the frequencies in the two tribes are similar to one another and, in so far as data are available, similar to the neighbouring Bantu-speaking tribes. The principal genetic difference between the Sandawe and the Nyaturu is in their frequencies of haemoglobin S and of glucose-6-phosphate dehydrogenase deficiency, both of which characters are several times higher in the Nyaturu than in the Sandawe; both characters are protective against falciparum malaria, and this suggests that the Nyaturu have in the past been much more strongly exposed to this infection than the Sandawe.

Sunshine and the geographical distribution of the alleles of the Gc system of plasma proteins.

Following the discovery by Daiger et al. (1975) that the Gc proteins of human plasma act as the carriers of vitamin D, the authors have plotted on a world map all available data on the frequency of the allele Gc2, and compared the distribution with that of sunlight. With some exceptions high frequencies of Gc2 correspond to low levels of sunlight and vice versa. Similar comparisons within Ireland show no such relation. The results are discussed in relation to natural selection and the incidence of rickets, due to vitamin D deficiency.