Hum. Hered. 25: 69-72 (1975)
Erythrocyte Adenosine Deaminase in Malaysians Q. B. W elch , L ijan E ng L ie-I njo and J. G anesan Department of Biology. University of Missouri, Kansas City, Mo.: G. W. Hooper Foundation, University of California, San Francisco, Calif., and Blood Genetics Division, Pusat Penyelidikan Perubatan (Institute for Medical Research), Kuala Lumpur
Key Words. Adenosine deaminase • Malaysians • Malays • Chinese • Indians • Gene frequencies Abstract. 944 adenosine deaminase phenotypings of Malay, Chinese, and Indian blood donors and newborns at Kuala Lumpur, Malaysia, yielded ADA1gene frequency estimates of 0.885 for the Malays, 0.939 for the Chinese, and 0.853 for the Indians.
Erythrocyte adenosine deaminase (ADA; EC 3.5.4.4) catalyzes the deamination of adenosine to ¡nosine in the first step of the adenosine purine salvage pathway. The first human population survey for ADA was reported by S pencer et al. [1968]. They found two alleles. ADA1 and ADA2, with a frequency of 0.05 for ADA2 among 1,353 English from around London [H opkinson et al., 1969]. They also found ADA polymorphism in the Indian (ADA2 frequency = 0.12) and Negro (ADA2 frequency = 0.03) populations they studied. We report the results of a survey among the Malay, Chinese, and Indian populations of West Malaysia.
Blood was systematically sampled from 601 donors at the Kuala Lumpur General Hospital Blood Bank and from 343 newborns in the Maternity Section. ADA phenotypes were determined by means of the electrophoresis and staining methods of S pencer et al. [1968], including the routine incubation of hemolysates with 2-mercaptoethanol prior to electrophoresis.
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Met ter ials and M et hods
W e lc h L ii -I njo G anlsan
70
Results (ind Discussion ADA2 frequency estimates arc 0.139, 0.057, and 0.162 for the Malay, Chinese, and Indian newborns, respectively (table I). These values are less than two standard errors (equivalent to 0.0455 significance level) from the ADA2 gene frequency estimates based on our total combined data: 0.115, 0.061. and 0.147 in Malays, Chinese, and Indians, respectively (table I). As table I shows, of the six groups only the Malay newborns deviated significantly (at the 5% level) from Hardy-Weinberg expectations. We can suggest no causal factors other than chance for this deviation. The finding that Malays near Kuala Lumpur and Filipinos in Seattle [Dhtter et a!.. 1970] both have an ADA2 gene frequency of 0.115 is com patible with a common origin for these two groups. S a n p iia k et ul. [1972] reported an ADA2 frequency of 0.08 among a sample from Northern Thai-
Table I. Adenosine deaminase phenotypes and gene frequencies among Malays. Chinese, and Indians in Malaysia Phenotypes !
2-1
2
obs.
exp.*
obs. exp.
obs. exp.
Mdluys Blood donors Newborns Totals
168 88 256
169.3 85.3 (254.5)
41 22 63
38.5 27.5 (66.2)
1 2.2 5 2.2 6 (4.3)
210 115 325
0.898 0.102 0.89 0.861 0.139 4.75* (0.885) (0.115) (0.76)
Chinese Blood donors Newborns Totals
143 101 244
143.6 101.4 (245.0)
22 13 35
20.6 12.3 (32.9)
0 0 0
0.7 0.4 (1.1)
165 114 279
0.933 0.067 0.76 0.943 0.057 0.37 (0.939) (0.061) (0.95)
Indians Blood donors Newborns Totals
166 82 248
167.5 80.1 (247.4)
57 27 84
53.7 31.0 (85.3)
3 5 8
0.138 0.85 4.3 226 0.861 3.0 114 0.838 0.162 1.90 (7.3) (340) (0.853) (0.147) (0.15)
total
Gene frequency estimates ADA1 ADA-
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( ) These expected values are not sums. but are based on totals. * Expected values assuming Hardy-Weinberg equilibrium. ** Significant at the 5% level.
A D A in Malaysians
71
land, and M c D hrmid et at. [1973] found the ADA- frequency to be 0.09 in the Batak of North Sumatra. Of our three Malaysian groups, the ADA2 gene frequency is lowest for Chinese (0.061); S hinoda [1970] found a lower value (0.031) for Japanese, and D exter et ul. [1970] an even lower value for ‘predominantly Japanese' in Seattle. The Indians in our sample, derived predominantly from Tamil-speaking South Indians, have a somewhat higher ADA2 frequency (0.147) than that (0.117) found by H opkinson et
Erythrocyte Adenosine Deaminase in Malaysians Q. B. W elch , L ijan E ng L ie-I njo and J. G anesan Department of Biology. University of Missouri, Kansas City, Mo.: G. W. Hooper Foundation, University of California, San Francisco, Calif., and Blood Genetics Division, Pusat Penyelidikan Perubatan (Institute for Medical Research), Kuala Lumpur
Key Words. Adenosine deaminase • Malaysians • Malays • Chinese • Indians • Gene frequencies Abstract. 944 adenosine deaminase phenotypings of Malay, Chinese, and Indian blood donors and newborns at Kuala Lumpur, Malaysia, yielded ADA1gene frequency estimates of 0.885 for the Malays, 0.939 for the Chinese, and 0.853 for the Indians.
Erythrocyte adenosine deaminase (ADA; EC 3.5.4.4) catalyzes the deamination of adenosine to ¡nosine in the first step of the adenosine purine salvage pathway. The first human population survey for ADA was reported by S pencer et al. [1968]. They found two alleles. ADA1 and ADA2, with a frequency of 0.05 for ADA2 among 1,353 English from around London [H opkinson et al., 1969]. They also found ADA polymorphism in the Indian (ADA2 frequency = 0.12) and Negro (ADA2 frequency = 0.03) populations they studied. We report the results of a survey among the Malay, Chinese, and Indian populations of West Malaysia.
Blood was systematically sampled from 601 donors at the Kuala Lumpur General Hospital Blood Bank and from 343 newborns in the Maternity Section. ADA phenotypes were determined by means of the electrophoresis and staining methods of S pencer et al. [1968], including the routine incubation of hemolysates with 2-mercaptoethanol prior to electrophoresis.
Downloaded by: Karolinska Institutet, University Library 130.237.122.245 - 1/18/2019 1:29:30 AM
Met ter ials and M et hods
W e lc h L ii -I njo G anlsan
70
Results (ind Discussion ADA2 frequency estimates arc 0.139, 0.057, and 0.162 for the Malay, Chinese, and Indian newborns, respectively (table I). These values are less than two standard errors (equivalent to 0.0455 significance level) from the ADA2 gene frequency estimates based on our total combined data: 0.115, 0.061. and 0.147 in Malays, Chinese, and Indians, respectively (table I). As table I shows, of the six groups only the Malay newborns deviated significantly (at the 5% level) from Hardy-Weinberg expectations. We can suggest no causal factors other than chance for this deviation. The finding that Malays near Kuala Lumpur and Filipinos in Seattle [Dhtter et a!.. 1970] both have an ADA2 gene frequency of 0.115 is com patible with a common origin for these two groups. S a n p iia k et ul. [1972] reported an ADA2 frequency of 0.08 among a sample from Northern Thai-
Table I. Adenosine deaminase phenotypes and gene frequencies among Malays. Chinese, and Indians in Malaysia Phenotypes !
2-1
2
obs.
exp.*
obs. exp.
obs. exp.
Mdluys Blood donors Newborns Totals
168 88 256
169.3 85.3 (254.5)
41 22 63
38.5 27.5 (66.2)
1 2.2 5 2.2 6 (4.3)
210 115 325
0.898 0.102 0.89 0.861 0.139 4.75* (0.885) (0.115) (0.76)
Chinese Blood donors Newborns Totals
143 101 244
143.6 101.4 (245.0)
22 13 35
20.6 12.3 (32.9)
0 0 0
0.7 0.4 (1.1)
165 114 279
0.933 0.067 0.76 0.943 0.057 0.37 (0.939) (0.061) (0.95)
Indians Blood donors Newborns Totals
166 82 248
167.5 80.1 (247.4)
57 27 84
53.7 31.0 (85.3)
3 5 8
0.138 0.85 4.3 226 0.861 3.0 114 0.838 0.162 1.90 (7.3) (340) (0.853) (0.147) (0.15)
total
Gene frequency estimates ADA1 ADA-
Downloaded by: Karolinska Institutet, University Library 130.237.122.245 - 1/18/2019 1:29:30 AM
( ) These expected values are not sums. but are based on totals. * Expected values assuming Hardy-Weinberg equilibrium. ** Significant at the 5% level.
A D A in Malaysians
71
land, and M c D hrmid et at. [1973] found the ADA- frequency to be 0.09 in the Batak of North Sumatra. Of our three Malaysian groups, the ADA2 gene frequency is lowest for Chinese (0.061); S hinoda [1970] found a lower value (0.031) for Japanese, and D exter et ul. [1970] an even lower value for ‘predominantly Japanese' in Seattle. The Indians in our sample, derived predominantly from Tamil-speaking South Indians, have a somewhat higher ADA2 frequency (0.147) than that (0.117) found by H opkinson et
