Sia Table 30 Nee Distribution of Haptoglobin Types in Micronesians From Rongelap Atoll Type 1-1 * Group AJ All Rongelap Selected* Rongelap No. in group 176 124 Observed % No. 33.5 59 33.1 41 Type 2-2 Expected, Observed No. % No. 39 18.2 32 - 13.3 19 Type 2-1 Observed Expected, No. “yo NO. 31.3 47.2 83 30.0 Expected, 0 and rare types, Observed No. 85.5 b2 No. Ll - 1.6 2 2 *Family groups include onlv one ¢hild (see text). in them. The Micronesian sera studied wereall transferrin type CC, which is the common European type. Considerable caution must be exercised in extrapolating to an entire population the genefre- quencies obtained from a small sample. This is particularly true when studying societies made up of small isolated or semi-isolated groups which one another, and, if superimposed, exhibit bi- modality with the antimode in the neighborhood of 1.75. With this point used as the division be- tween high and low excretors, it is estimated that _nearly 90% of the Rongelapese are high excretors. A breakdownof this population into exposed and unexposed groups showsalmost identical mean BAIB excretion values for the two (exposed, 2.07 + £ compartmentalize the breeding community. Thus, and America the frequencyof type 1-1 is higher in populations living near the equator than in those remote from it. It is clear from the Micronesian studies that, at least in some cases, an individual may have no haptoglobin at one time, but have sufficient haptoglobin to permit typing at another time. (In this case, the interval was 2 years.) Examination of the ahaptoglobinemic individuals gave no significant findings. With =% of the Rongelap population sampled, all the ahaptoglobinemic individualsfell into one family grouping. This did not help to elucidate the genetic pattern, except to make it appear unlikely that the Hp’ allele, if such exists, is not at the same locus as the Hp' and Hp?’alleles. Oneofthe sibs of an ahaptoglobinemic was a type* 2-1, x B-Amino-iso-butyric Acid (BAIB) Levels. Figure . 46 showsthe frequencydistribution of BATB excretion for the Rongelapese and that of a New York City white population for comparison. The two distributions are essentially complementaryto FREQUENCY (PERCENT) fu w T the Rongelapese appearto havea fairly highfre- quency of type 1-1, consistent with the general (though not exclusive) rule that in Europe-Africa AMERICAN WHITES 10 c 2 wi Oo a wa a 5 20 2.5 N=(88 J { Vv Zz ui 35 fe) Lud x Lo 1.0 5 2.0 mg BAIB 2.5 3.0 CREATININE, Figure +6. Frequency distributions of urinary excretion rates of 8-amino-2se-butyric acid of Marshal] Islanders (Rongelap} and U.S. whites. TTT Me were visible; two of these were very faint 2-2’s, but the fastest-moving haptoglobin band was not seen