Genetic polymorphisms in Utsjoki Lapps

M.-R. ESKOLA, M. KIRJARINTA, L.E. NIJENHUIS, E. VAN DEN BERG-LOONEN, E. VAN LOGHEM, M. ISOKOSKl, T. SAHi, and A.W. ERIKSSON

. ated in The blood groups of 172 Utsjoki Lapps were inve~tig. iand June 1973. utsjoki is the northernmost commune i.n Fi.n 5 ed and about 85 per cent of the population is still colllPo

of Lapps, the so-called Mountain I.apps • h 1.. c Figures 1-4 show the percentages of some polytOOrJ? 1 blood groups, senmi proteins , and red cel1 enzymes n :re different Fennoscandian populations. The utsjoki r..apps a denoted with black. The next four populations are other _... Pi is · the ne~""" nn h Lapp populations in the conmune of Jnari' Genetic poly·IrOrphisms in Lapps 189

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123l~6 789 10 1 2 3 l 5 6 7 8 9 10 1 2 3 l 5 6 7 8 9 10 1 2 3 I. 5 6 7 8 9 10 A2 B NS r (cde)

Figure 1 Approximate blood group gene frequencies in some Fennoscandian populations (1, Utsjoki Lapps; 2, Inari Mountain Lapps , 3, Inari Fisher Lapps; 4, Sevettij~rvi Skolt Lapps; 5, Nellirn Skolt Lapps; 6, Norwegian L3.pps; 7, SWedish Lapps, 8, , northeastern ; 9, Finns, whole country; 10, Norwegians and swedes)

two are Norweg ian and SWedish Lapps, and the last three are Finns, Norwegians, and Swedes, in other words non-Iappish populations. In the ABO blood group system (Figure 1) the 2 gene A can be considered typical of Lapps. The frequency of this gene is considerably higher in Lapp populations than in non-Lapps. There is no definite distribution pat­ tern for the gene B. The Skolt Lapps have a very high frequency, while in the Fisher Lapps the gene B is al­ most absent. The estimated frequency of the gene complex NS is around 7 per cent for Caucasians. Here, the Utsjoki Lapps differ markedly from other Finnish Lapps, and resemble the Norwegian and SWedish Lapps in having a much higher fre­ quency. The frequency of Rhesus-negative subjects is clearly tnuch lower in all Lapp populations than in non-Lapps· For the gene P , the approximate value for Europeans is SO per cent; the ~pps, with the exception of the Utsjoki Lapps (51 per cent), all have lower frequencies. The frequency of the Fya {Duffy) is well above the Euro­ I>ean average, which is about 40 per cent; in all the Lapp populations it is over 50 per cent, and among the Finni.sh Skolt Lapps it is as high as 70 per cent. In the Kell system there are no marked differences be­ ~een the different populations, the frequency of the gene being rather low. 190 Genetic considerations

LEWtS (o+) O/o AB H -nonsecretors

L. 0

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"--~-- I CEL AN DE R S ICELANOERS --30

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MARIS ( Mountain)

L....-___ _ F l N N 5 ( Helsink i) 15 FINNS ( Centrol and S-Finlond 1---___, MARIS ( Meodow ....__ _ _ ---i 10 FINNS (NE - Finland}- ----f

SEVETTIJARVI.. SKOLTS ------f5 ~ --- SEVNE LLlETTIJARVfM SKOL TSSKOLT S NELLIM SKOLTS _ _ INARI MOUNTAIN LAPPS INARI FISHER LAPPS ~-~~=~~- INARI FISHER LAPPS INARI MOUNTAIN LAl'PS ESKIMOS ( A'nilagtok ) ESKIMOS (Augpilogtok) UTSJOK I LA S

The Fiqure 2 frequency Of Lew1. s {a+) and ABH non-secre tors in selected populations

Abtost all subjects with the lewis antigen. Le (a+} aref also ABH non-secretors (Figure 2). About 25 per cent 0 western Europeans (e.g. Icelanders) have the antigen. and Le Ma(a+). Rowever, the Finno-Ugrian populations' Finns ch iawer ns• i iving· . on the Volga bend in. th e USSR ' have . muthe ut- frequencies. All the Finnish Lapps, and especially SJ·ok i · Laws, have extremely low frequencies· of theseastern b:ai.ts (<5 per cent) . This could be considered ~de far halJ1· fl uence, since· the ~ngoloid· Pop ulations· s tudie s a 0 ve ahiost zero frequencies of the genes se and Le·ther • for 'Ibree different samples of Finns have b een typed. eiclosest Le(a) or ABB. The Finns fron1 NE Finland, who live to the Iapps , haVe the lowest frequencies · Genetic polymorphism5 in Lapps 191

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1 23l56789 1 23l 567 89 123l589 Hp, Gc 2 Inv 1 Figure 3 Approximate gene frequencies of serum groups in some Fennoscandian populations (1, ·utsjoki Lapps, 2, Inari Mountain Lapps; 3, Inari Fisher Lapps; 4, Sevettijarvi Skolt Lapps; 5, Nellim Skolt Lapps; 6, Norwegian Lapps, ?, Swedish Lapps; 8, Finns; 9, Norwegians and SWedes) 1 The frequency of the haptoglobin gene Hp (Figure 3) is roughly the same throughout most of the European continent, ranging from 35 to 43 per cent. The Utsjoki Lapps and Inari ~untain Lapps have frequencies well below 30 per cent. 2 The group-specific component gene Gc shows a very ~~terogeneous pattern, only 3 per cent among the Inari. isher Lapps and as high as 33 per cent anong the Nellim Skol t Lapps . The only variants of the transferrin system in the Iapp populations are the phenotypes B0_ 1 and CDChi, but their frequencies are much lower than among other Finno-Ugrian populations (1). Of the 168 Utsjoki sera, only three were of the slow-moving variant type CDChi · . The frequency of the Inv1 {Kml) gene anong the Lapps is two- to five-fold that of other Nordic populations. For the Sevettij~rvi Skolt Lapps the frequency is more than twice as high as any previously reported in European populations (3) • In the Gm system the haplotype zag is nvre frequent than in other Europeans whereas fnb is much rarer· The fr I t equency of zag is 26 per cent and of fnb 35 per cen • 192 Genetic considerations

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123l.56789 123~56789 12345789 pc 2 2 PGM 1 ADA

Fiqure 4 Approximate gene frequencies for red cell en­ zymes in some Fennoscandian populations ( 1, Uts j oki Lapps: 2, Inari Moun~ain Lapps, 3, Inari Fisher Lapps; 4, Sevetti- jArvi Slcolt Lapps; 5, Nellim Skolt Lapps; 6, Norwegian ) Lapps; 7, Swedish Lapps; 8, Finns; 9, Norwegians and swedes

As for the BL-A frequencies of the Utsjoki Lapps, the most striking differences, in comparison with other Euro­ pean populations, are the high frequencies of HL-A, 3 / 9 ' 27, W 15 and W 20, and the low frequencies of HlrA 1, 8 ' and 12 • As canpared with the other Caucasian populations'

the Iapps show higher frequencies of HL-A 3 and W 15 1 and low frequencies of HL-A 12 (4) . As in other Europeans, no polyioorphism was found for the ~m ma:rkers, the sanple being 100 per cent A-zn (1+2-) • In this respect these Lapps differ f rcm Eskimos, in whom P<>lYDDrphism_ for the Atn mark.er has been found. The. degree of( Polymorphism in the red cell enzymes is rather high F'igure 4) • e.9. the acid phosphatase gene p C has a fre - q~ncy in all Finnish Lapp populations that ranks among the highest in the world. Of the Caucasian populations only the Hahbanite Jews have a Phosphoglucanutase gene PGM 2 frequency higher than 1 SO per cent. With the exception of the Finnish Skolt r.apps' allqene. the Lapp Populations have high frequencies of this

The frequency of the adenylate kinase gene AK2 in Lapp PC>Pul.a tions 18· · · ab . 2 very low; among the Skolt Lapps it 1s almost sent < >. The only cases with the phenotype AK 1-2 could Genetic polymorphisms in Lapps 193

be traced to Finnish ancestry. The adenosine deaminase gene ADA 2 has very high fre- quencies, especially in the Utsjoki Lapp population. The results confirm that in so far as genetic markers are concerned the Utsjoki Lapps, like other Lapp popula­ tions, have several characteristics distinguishing them from the neighbouring non-Lappish populations. Which of these differing characteristics are due to isolation, gene­ tic drift, or the founder effect is difficult to say.

ACKNOWLEDGMENT

This study was aided by grants from the Nordic Council for Arctic Medical Research and the Free University, Amsterdam.

SUMMARY

A genetic survey of 172 Utsjoki Lapps from Finnish Lapland included tests of red cell antigens, sermn groups, red cell enzymes, and secretion of ABH antigens. The Utsjoki Lapps had high frequencies of the genes A , NS, Fya, R1, R2, and 2 2 PGM12 , and low frequencies of the genes Ai, MS, r, and Gc . The frequency of ABH non-secretors was also -ve.ry low. The frequencies found fit well into the range reported for neighbouring Lapp populations of .

REFERENCES

1. Eriksson, A. w., "Genetic polymorphisms in Finno-Ugrian populations: Finns, Lapps and Maris," Israel J - med. Sci., 9: 1156-70 (1973} 2 · Eriksson, A.W., Fellman, J., Kirjarinta, M., Eskola, M.-R. , Singh, s. , Benkmann, H. -G. , Goedde, H. W·, Mourant, A .E., Tills, D. , and Lehmann, W. , "Adenylate kinase polymorphism in populations in Finland (swedes, Finns , Lapps) , in Maris , and in Greenland Eskimos, " Hum. Genet., 12: 123-30 (1971) 3 · Steinberg, A.G., Tiilikainen, A., Eskola, M.-R., and Eriksson, A. w., "Gammaglobulin allotypes in Finnish Lapps, Aland Islanders, Maris (Cheremis) , and Greenland Eskimos," Am. J. hum. Genet., 26: 223-43 (1974) 4• Tiilikainen, A., Eriksson, A.W., McQueen, J.M., and Amos, D.B., "The Hl-A system in the Skolt Lapp popula­ tion, " Monogr. His tocCIIlpatibility Testing (Copenhagen: Munksgaard, 1972), pp. 85-92