Table 2.
Comparisons with Published Lactose-Digester Frequencies in Matching Populations, Taking into Account Sampling and Phenotyping Error[Note]
| Group | Country of Genotyped Sample(No.) | Expected Frequency ofLactose Digesters | Country ofPhenotyped Sample(No.) | Test Method | Observed Frequency ofLactose Digesters inPhenotyped Sample | Reference | P Value |
| Fulbea | Cameroon (n = 49) | .265 | Nigeria (n = 24) | Blood glucose | .292 | Kretchmer et al. 1971 | 1 |
| Hausa | Cameroon (n = 18) | .305 | Nigeria (n = 17) | Blood glucose | .235 | Kretchmer et al. 1971 | .749 |
| Wolof | Senegal (n = 69) | .086 | Senegal (n = 53) | Blood glucose | .509 | Arnold et al. 1980 | 0 |
| Ga’ali (Jaali) | Sudan (North) (n = 30) | .068 | Sudan (n = 113) | Breath hydrogen | .531 | Bayoumi et al. 1981 | 0 |
| Shaigi | Sudan (North) (n = 11) | .068 | Sudan (n = 42) | Breath hydrogen | .381 | Bayoumi et al. 1981 | .025 |
| Nuer | Sudan (South), Ethiopia (n = 132) | .068 | Sudan (n = 23) | Breath hydrogen | .217 | Bayoumi et al. 1982 | .030 |
| Dinka | Sudan (South) (n = 34) | .068 | Sudan (n = 208) | Breath hydrogen | .255 | Bayoumi et al. 1982 | .001 |
| European | Ireland (n = 47) | .918 | Ireland (n = 50) | Blood glucose | .900 | Fielding et al. 1981b | 1 |
Note.— Expected frequency of lactose digesters, taking into account the test error rate by the method used in the matched population = Ltrue(1−fp) + (1−Ltrue)fn, where Ltrue = frequency of CT + TT genotypes assuming Hardy-Weinberg equilibrium, (fn,fp) = (10/116, 5/73) if the blood glucose test method is used and (fn,fp) = (9/132, 5/120) if the breath hydrogen test method is used. P value = result of test described in the “Statistical Analysis” section.
a
Fulbe with a sedentary lifestyle.
b
Blood glucose results only taken from this source, by use of a rise of >20 mg/dl to define lactose digester.