planning of biobanks. The genealogy plays an important role in the imputation of untyped individuals. Still, even without it, haplotypes could be imputed into a proband if the mate and at least one child are genotyped, with the other relatives used to assist in resolving phase uncertainties, e.g. when both mate and child are heterozygous. With high density SNP data, close relationships could often be detected and it may be possible to reconstruct small families. It remains to be seen, with further methodological development, whether information on the mitochondria, the sex chromosomes and knowledge of ancestries/ethnicities of the proband and mate could assist in haplotype imputation. Recently, as a consequence of the unprecedented success of case-control genome-wide association studies, family-based studies have faded into the background. The results presented here are a reminder of the fact that genetics is ultimately a study of inheritance. Familial relations always play an important role and sometimes in unexpected ways.
