Defective Colour Vision, P.T.C. Tasting and Drepanocytosis in Samples From Fifteen Brazilian Populations

Kalmus, H.

doi:10.1111/j.1469-1809.1972.tb00202.x

Cited by 39 publications

(15 citation statements)

References 3 publications

(4 reference statements)

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“…The total sample was not large enough to allow reliable studies on gene frequencies within racial subgroups and/or type of surnames. The Hb gene fre- quencies observed here are in agreement with all the other studies in Bahia [Azevedo et al, 1980] but one [Kalmus, 1957]. Table III shows the marked changes in the proportions of whites, mulattoes and blacks over the last 90 years.…”

Section: Resultssupporting

confidence: 82%

“…Presently, the population of the island is highly mixed and is estimated to about 9,750 inhabitants [IBGE, 1980]. Kalmus [1957] reported 16% sicklers among 70 inhabitants of Itaparica, a sur prisingly high frequency in a review of all sickle cell studies carried out in the State of Bahia [Azevedo et al, 1980]. This paper presents the frequencies of ab normal hemoglobins (Hb), glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD), as de termined among school children of Itaparica, and a historical reconstruction of the racial admixture process in the island on the basis of death certificates over the last 90 years.…”

mentioning

confidence: 99%

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Genetic and Anthropological Studies in the Island of Itaparica, Bahia, Brazil

Azevêdo¹,

Silva²,

Silva³

et al. 1981

Hum Hered

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The ongoing racial admixture was studied in the island of Itaparica off the coast of the State of Bahia, in Brazil. The following gene frequencies were observed: Hb S = 0.039; Hb C = 0.022; PGD C = 0.024; Gd A = 0.217 and Gd Ā = 0.052, among 293 mixed school children whose black phenotype index (medium mulatto + dark mulatto + black/total) was 0.457. Data on racial groups, obtained from 898 death certificates of three periods (1889–1890, 1934–1937 and 1975–1980) showed that in about 90 years (three generations) the proportion of mulattoes had doubled, the whites had decreased to one third, and the blacks showed no variation. Changes in the frequencies of surnames within the whites over the same 90 years indicated a growing proportion of individuals with black ancestry flowing into the white group. Higher reproductive rates among the more negroid individuals is probably the leading force directing the racial admixture in the island.

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Section: Resultssupporting

confidence: 82%

mentioning

confidence: 99%

Genetic and Anthropological Studies in the Island of Itaparica, Bahia, Brazil

Azevêdo¹,

Silva²,

Silva³

et al. 1981

Hum Hered

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“…Apart from the value reported by K almus [8] among mixed Brazilian blacks, our values are not close to any of the other values for black popula tions.…”

Section: Discussioncontrasting

confidence: 40%

“…Barnicot [1] has reported that the frequency of non-tasters among West African blacks is 2.7% (gene frequency of 0.164) and Kalmus [8] reported a frequency of 11.55% (gene frequency of 0.339) among mixed Brazilian blacks.…”

Section: Discussionmentioning

confidence: 99%

Genetic Variation in Nigeria

Scott-Emuakpor¹,

Uviovo²,

Warren³

1975

Hum Hered

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Phenylthiourea (PTC) taste sensitivity thresholds have been measured for 2,013 Nigerians using a modified sorting technique. The frequency of non-tasters was observed to be 12.5% and the t gene frequency was 0.354. There was a significant difference between the sexes at the 0.01 level for the overall population. However, when the data are analyzed according to the geographical origin of the subject, the sex difference is found only in one of three geographical regions. Also, there may be geographical influences on PTC taste sensitivity, although this was not statistically significant. The estimates reported in this population differ considerably from some of the previously published estimates for black populations.

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“…It is unfortunate th at no samples are available from mainland Spain for comparison, and the only indication there is of frequencies in the Iberian peninsula comes from the derived populations of the new world. A Spanish/American sample (Garth, 1933(Garth, , 1936) gave a frequency of 3.8% , 13 males being colourblind out of a sample of 346, while the two Brazilian white male samples tested by Kalrnus (Kalmus, 1957), in which the Portugese ancestry was appreciable, gave incidences of 11 out of 147 (7.5%) and 17 out of 247 (6.9%). It is not clear how much of the ancestry of these samples was derived from non-Iberian sources, but if it is assumed th at these were American Indian or Negro, in both of whom colourblind ness is less frequent than in European, the figures can be regarded as minimal estimates of the Iberian frequencies.…”

Section: Discussionmentioning

confidence: 99%