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Measurements of likeness in relatives of trisomies
Author(s) -
PENROSE L. S.
Publication year - 1963
Publication title -
annals of human genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.537
H-Index - 77
eISSN - 1469-1809
pISSN - 0003-4800
DOI - 10.1111/j.1469-1809.1963.tb00211.x
Subject(s) - parthenogenesis , genetics , heterozygote advantage , chromosome , allele , biology , gene , embryo
SUMMARY The significance of correlation coefficients for measuring likenesses between trisomies, their parents and sibs is discussed. Expected formulae and values are given which are based on three different assumptions about non‐disjunction. The most marked distinction is found between correlations for trisomic child and aberrant parent, in whom non‐disjunction has occurred, and that for trisomic child and parent with normal gametes. Observations on measurements of maximal old palmar angle are discussed. I would like to express my thanks to Mrs Sheila Maynard Smith who has kindly calculated independently all the formulae used in this paper. I am particularly indebted to her for drawing my attention to the proportions of the different types of chromosome pairs in aberrant gametes from heterozygotes when there is 50 % recombination. The frequencies of the types AA, Aa, aA and aa are in the ratio 1:2:2:1 and not in the apparently more likely ratio 1:1:1:1. This peculiarity had been pointed out by Prof. J. B. S. Haldane in the discussion of the formal consequences of parthenogenesis.