INHERITANCE OF THE P.T.C. TASTE CHARACTER IN MAN: AN ANALYSIS OF 126 RÁTRHI BRAHMIN FAMILIES OF WEST BENGAL

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Abstract
Summary: 1. P.T.C. taste threshold data for 127 families have been given, of which one family has been rejected on account of illegitimacy.2. A x2 test by the ‘2×2’ contingency table indicates that the matings in the families studied were random (x2= 097, P>0.3).3. Analysis of the families by Fisher's method following Race & Sanger (1954) indicated a ‘good fit’ (P > 0.1) between the observed and the expected numbers of T × T as well as T×t (including t×T) families.4. Fisher's test following Smith (1956) indicated a ‘good fit’ (P>0.1) for the totals of families of each of the types T×T and T × t (also t × T)–each family containing at least one non‐taster child. But a significant discrepancy (PP>002).6. Discrepancies have been noticed between the observed and the expected numbers of non‐taster children in the combined family sizes 2 and 3 out of T × T matings, and the family size 4 out of T×t (and t×T) matings–each producing at least one non‐taster child (Px2 values for families of all sizes (calculated separately for each size) in respect of the numbers of non‐taster children indicated a significant discrepancy (P< 0.02) for T×T families, but a satisfactory agreement (P>0.05) for the T×t (including t×T) families–each family containing at least one non‐taster child.8. Summing up the x2 values calculated on totals under the four different tests following Smith (1956), a single x2 of 13–38 with 4 D.F. was obtained, which finally indicated a significant divergence (P< 0.01) between the theory and the data taken as a whole.9. It has been suggested that an assumption of incomplete penetrance (say, about 90 %) of the dominant taste gene might interpret the entire P.T.C. data (including the sib‐pair data of Harris & Kalmus, and Das referred to already) more satisfactorily than the simple hypothesis as it stands to‐day.