Genetic analysis of cleft lip and cleft palate in southern Poland. II. Complex segregation analysis

A complex segregation analysis based on the maximum likelihood method was applied on a sample of 329 families with CP and 687 families with CL +/- P. The results for CP malformations were equivocal, since the authors were unable to distinguish between the hypothesis of recessive inheritance with complete penetrance (chi 2 = 19.60) and that of multifactorial inheritance (chi 2 = 20.38). For CL +/- P lesions the most plausible hypothesis seemed to be that of dominant inheritance with low penetrance (t = 0.277) and relatively high frequency of phenocopies. For these hypotheses the values Q of theoretical recurrence risk were computed and presented.