[Empirical estimation of recurrence risk in diseases with variable age-at-onset: correction]

Combinatorial approach in empirical estimation of recurrence risks in variable age-at-onset (AO) was elaborated in [2], where special combinatorial coefficient was introduced, the so called "constrained polynomial coefficient", which permit to count the permutations of AO-sibling classes, constrained by their age to the time of study (ATS). Unfortunately giving account of method of calculation md--the table morbidity rate--for siblings of age d in [2] were not introduced limitations for AO or ATS of those siblings, which were affected before or not yet reached the age d under evaluation. Lack of the limitations result in the estimate of prevalence (i.e. the proportion of affected siblings, with the given AO, among all the siblings), but not incidence or age-specific morbidity rate (i.e. the proportion of the siblings, affected in the d-th age interval among those siblings, who reached and/or outlive the age d, being free of disease before the age d under evaluation). In this communication the oversight is removed and the method of calculation of md is simplified: only the two classes instead of a lot of the possible AO-classes of siblings are considered, namely--"affected in the d-th age interval" and "health in the d-th age interval" under evaluation. Thus, the way of calculation of md may be reduced to the simple binomial case.