Deviating segregations in families with elliptocytosis II

Abstract

An analysis has been performed of various pedigrees with elliptocytosis in which this rare, dominant trait could not be shown to be linked with rhesus. As in the case of rhesus-linked elliptocytosis segregations have been observed to deviate from the expected. Some indication has been found that theCDe:cde segregation may deviate from the expected in such a way that an excess ofCDe alleles would occur in not-O individuals (blood groups A, B and AB), but that this deviating segregation would be absent from O individuals.

TheEl+ :El- (= carriers of the trait:: non-carriers) segregation shows a significant excess ofEl+ children fromEl+ mothers (and, in part of the pedigrees at the same time a deficiency ofEl+ children fromEl+ fathers). The excess appears to originate fromCcDee, ccddee orccDee,El+ mothers; no excess ofEl+ was observed in children fromEl+ mothers withCCDee or rhesus factorE containing rhesus types.

The paternal gene contribution appeared also to be correlated with the excess ofEl+ children fromEl+ mothers: the majority of O children withc alleles inherited from their fathers and of not-O, female children receivingC from their fathers appeared to be elliptocytosis carriers; all other combinations of sex, ABO blood groups and ofC orc rhesus factors originating from the fathers, failed to show any excess ofEl+. It is suggested that selective fertilization is the most acceptable explanation for the observed phenomena.

As a consequence of this hypothesis it will be necessary to suppose an additional hypothesis of either a selective fertilization or a selective elimination of one of the two egg cell nuclei following second meiosis: in the present material nuclei with the elliptocytosis inducing alleles are generally favoured, those with the normal allele represent alternatively the nuclei to be selectively eliminated.