Jewish Population Groups in Israel CHAIAM SHEBA, ISRAEL ASHKENAZI and ARYEH SZEINBERG
Total Page:16
File Type:pdf, Size:1020Kb
Taste Sensitivity to Phenylthiourea among the Jewish Population Groups in Israel CHAIAM SHEBA, ISRAEL ASHKENAZI AND ARYEH SZEINBERG Government Hospital, Tel Hashomer, Israel THE JEWISH NATION which settled on the Eastern Mediterranean shores about 12 centuries B.C. has been dispersed to different parts of the world for more than 2,000 years. Guarded by strict observance of religious laws, the Jews succeeded in preserving their national identity among the indigenous popula- tions, through intermarriage and other forms of mixing with local populations, particularly during times of national and social upheavals, are known. From the point of view of the genetics of human populations it is, therefore, of great interest to investigate the similarities and differences among the various Jewish communities as well as in relation to local population groups. The State of Israel, where during a comparatively short period a gathering of the dispersed Jewish tribes from the whole world took place, presents a unique opportunity for the study of such a problem. Several genetic traits, namely blood group distribution, fingerprint patterns, the occurrence of an inherited glucose-6-phosphate dehydrogenase deficiency in erythrocytes and the distribution of Familial Mediterranean Fever, have been extensively in- vestigated in the various Jewish communities in Israel (Mourant et al., 1958; Sachs and Bat-Miriam, 1957: Szeinberg et al., 1958; Heller et al., 1960). Little information exists about the distribution among the Jews, of another genetically determined trait, namely that of taste sensitivity to phenylthiourea. The results of our investigations of this trait are summarized in the present communication. METHODS The examinations were performed by the sorting technique of Harris and Kalmus (1949). Solution No. 1 contained 0.13 Gm. phenylthiourea per 100 ml. of tap water, the subsequent solutions (up to 13) were prepared by serial two-fold dilutions. The majority of the subjects were 8-22 years old. Relatives closer than first cousins have not been included in the material. All the subjects investigated were either immigrants or belonged to the first generation born in Israel. RESULTS A well defined bimodal distribution of the taste sensitivity was observed in all the communities investigated (table 1). The modes among the tasters were characterized by sharp peaks in solution No. 9 or 10 with the exception of Received June 22, 1961. This investigation has been aided by (Grant No. RF: 60101 from the Rockefeller Foundation. 44 SHEBA ET AL. 45 -1 0 _-11 d! r- D V U asN N Co _--1 m o - L- O 0 "to %0 d11 %C %D 4 L- ee%C N %CD N id dv1-%O10 CD N N d11 " N d E-4 C" ce I _Q _ f) I _-4 .4 P- " C 4 N N d e1 N 1-b " N 0 11n N ON 0 0 0 0 0 C 0 -" r " U) N _ Nme qt N 10 - 00 O -q.1 Nq _ - E-4 N -1t.- 51-- dI 00 N t 00N -0 --1 0 0 0 'l -~ N N N N U) ¢ -N1 I 0 en m _ N Ns td 00 cr) %D 1- N en em en enen D0 _ N 1-4 1- 0.4" onU) 0' en t) 't 0% - 4 z I U) I 00 emn O I~- 0d 0 0) - -1in N _ N , C) 0 00 N 0 P- 0 0 0 N mn u) ¢ - _ NmN 0 00 0 H 6 z a e 0 0 11-I m d p4 1-4 w 4t 0_ O~~~~~~~OOO Nq N 00 - < o o o zb4 U) m t N - mn eq C t 0_1- Ui) 0 _ _ m NLI.4N ,t " - 00 N N m U. N .000d' d 1-00 en so (7 N "- m C' _, 0mm-" tN 1-LAO')t 1-C0N m L- N N 'I dOC 0 7- "- 00 u N N NN1. N qt No 10 .4L _j t Qk _4 x O U) 'W C 'd U) C) Co Cuj E- N sCuSC) - U)E Co Ul¢ I Z; c c.E X ZA co -O X1c C) 0 0 C.b 46 TASTE SENSITIVITY IN ISRAEL the Gerba community (however, in that community the investigated sample was too small to permit definite conclusions). Among the non-tasters the modes were not so well defined, possibly owing to the relatively small num- bers of subjects in each group. The antimode was in all cases at the solution No. 5 (in the subsequent analysis the few subjects with taste threshold at this solution were included among the non-tasters). TABLE 2. MEAN THRESHOLDS AND MODES OF TASTERS Total Males Females Taste . Taste Taste threshold threshold 'threshold Count No. Of Mean ± No. of Mean ± No. of Mean ± ofgin subjects St. Dev. Mode subjects St. Dev. Mode subjects St. Dev. Mode North. Africa 289 9.57±1.59 9 155 9.14±1.58 9 134 9.36±1.56 9 Kurdistan 111 9.57±1.47 9 56 9.33±1.59 9 55 9.63±1.32 9 Iraq & Persia 282 9.60±1.33 9 145 9.46X1.32 9 137 9.76±|1.33 9 Yemen 214 9.59±1.39 10 108 9.71±1.47 10 106 9.47±1.30 10 Europe Ashkenazim 349 9.50±e1.59 9 179 9.18±1.56 9 170 9.83±1.54 9 Balkan Non Ashke- nazim 79 9.60±1.32 10 30 9.40±! 0.99 9 49 9.73±1.50 10 The mean threshold among tasters from Gerba was 8.4. In the other com- munities it varied between 9.1 and 9.8 according to the sex and origin of the subjects (table 2). With one exception (Yemen), the mean threshold of tasters was 'always higher in females than in males, but statistically signfficant differences between sexes were found only within the Ashkenazi and the North African groups (table 3). Statistically significant differences between com- munities regarding the mean threshold among the tasters were found (table 3) between (1) males from Yemen and those of North African or Ashkenazic origin, and (2) males from North Africa and those from Iraq and Iran. TABLE 3. MEAN THRESHOLDS AMONG TASTERS: STATISTICAL ANALYSIS OF THE RESULTS N._of subiects Community Sex investigated t P Ashkenazim Males vs. Females 347 3.814 P<0.001 N. Africa " " " 287 2.610 P<0.01 N. Africa vs. Yemen " " Males 261 2.915 P<0.01 N. Africa vs. Iraq Pt " 298 2.885 P<0.01 Ashkenazim vs. Yemen " " " 283 2.807 P<0.01 The relative frequencies of non-tasters in the various communities are pre- sented in table 4. Intersex differences were statistically significant only in the SHEBA ET AL. 47 North African community, in which a higher frequency of non-tasters among females than among males was observed (table 5). The highest frequency of non-tasters was observed in the Gerba and Cochin communities (41 and 31 per cent, respectively). The statistical analysis dem- onstrated that these two communities differed significantly from most of the other groups (table 5). It should be stressed, however, that only small sam- TABLE 4: FREQUENCY OF NON-TASTERS Total Males Females Countyof No. of % of non. No. of % of non- No. of % of non- origin subjects tasters subjects tasters subjects tasters Kurdistan 129 13.95±1-3.05 64 12.50± 4.13 65 15.38± 4.48 North- 340 15.00±1.94 174 10.91± 2.38 166 19.37+ 3.07 Africa' Iraq & 336 16.07±2.00 167 13.17± 2.62 169 18.93± 3.01 Persia Yemen 261 18.00±2.38 132 18.18± 3.36 129 17.82± 3.37 Europe- 440 20.68±1.93 227 21.14± 2.71 213 20.18± 2.75 Ashkenazim2 Balkan-Non- 101 21.78±4.11 41 26.82± 6.92 60 18.33± 4.99 Ashkenai Cochin 41 31.70±7.27 20 30.00±10.25 21 33.33+10.29 Gerba 41 41.46+7.69 14 50.00±13.36 27 37.03± 9.29 lThe results pertaining to the North African Jews comprise the findings among sub- jects from Tunisia (97), Morocco (184) and Tripolitania (59). As no significant dif- ferences were found between these groups they are presenetd as one community. 'A separate analysis was also performed for two groups of Ashkenazi subjects: (a) those originating from Poland, Western Russia, and Lithuania (number of subjects 319, fre- quency of non-tasters 20.8 per cent; (b) subjects from Roumania, Hungary and Czecho- slovakia (number of subjects 121, frequency of non-tasters 20.5 per cent). There is ex- cellent agreement between their frequencies and consequently all Ashkenazi Jews are presented as one group. ples from Gerba and Cochin communities have been examined, owing to the high rate of consanguinity and the necessity of exclusion of close relatives from the investigated material. The comparison between other groups is complicated by different findings among males and females. A close similarity in the frequency of non-tasters was observed among the Ashkenazi females and those from North Africa, Kurdistan, Iraq, Persia, Yemen and the Balkan countries (15.4 - 20.1 per cent non-tasters). On the other hand, some statistically significant differences were seen between males from these communities. A low frequency of non- tasters was found among the males from North Africa, Kurdistan, Iraq, and Persia (10.9 - 13.1 per cent), while a much higher frequency was seen among the Ashkenazi and non-Ashkenazi (Balkan) males from Europe (21.1 - 26.8 per cent respectively, tables 4 and 5).