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Biomedical subjects

D Tills

Publications and source records attributed to D Tills.

47 records · Page 3Linked to original sources

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.

Blood Group Antigens↗

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.

ABO Blood-Group System↗

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.

Blood Group Antigens↗

Blood group variation in the Isle of Lewis.

Blood groups and protein and enzyme polymorphism distributions were studied in 285 residents on the Isle of Lewis, in the Outer Hebrides. As well as gene frequency calculations for individual loci, genetic distance estimations were made and a phylogenetic tree was constructed. The results indicated several major differences from North-west European populations, with high values of R2(CDe), Rz(CDE) and P1. Among protein and enzyme polymorphisms Hp1, EAPA and PGM1(1) had very high frequencies. Genetic distances show Lewis to be unlike both Western and Eastern North European populations, while the phylogenetic tree shows a common, but rather distant, ancestry with Icelanders. This genetic uniqueness of Lewis as a whole is accompanied by a considerable degree of heterogeneity within the island itself, especially in the ABO and Rh systems. Stornoway, with a greater proportion of residents descended from immigrant stock, shows a greater degree of similarity with neighbouring populations. The reasons for both the overall uniqueness and the heterogeneity within Lewis are discussed, but in the absence of a large time-depth and adequate vital records, the various roles of selection, drift and migration in producing them are difficult to establish.

ABO Blood-Group System↗