Caste variation in the distribution of placental alkaline phosphatase genes among the Hindus of West Bengal.
798 placentas (Brahmin 141, Kayastha 303, Mahishya 91 and mixed low castes 263), from Calcutta hospitals, have been studied by starch gel electrophoresis for alkaline phosphatase types. The estimated gene-frequencies resemble those found else-where in caucasoid populations. Statistically significant differences (P approximately 0.02) were, however, noticed between the broadly divided upper caste group (Brahmin and Kayastha) and the lower caste group (Mahishya and mixed low castes) in respect of Plf 1 and Pls 1) gene distributions. The upper caste group has higher Plf 1 and lower Pls 1 frequencies than the lower caste group. The two broad caste groups are, however, quite uniform in Pli 1 distribution. All the six common phenotypes (S1, F1, I 1, S1F1, S1 I 1 and F1 I 1) and seven rare phenotypes (S1S2, S1S3, F1F2, F1S2, F2S1, F1S3 and I 1S2) were found.