A statistical segregation analysis of seven families with inherited (21q22q)-tranlocations is carried out. The risk figure for Down’s syndrome in the offspring of female carriers is estimated to be 8.9%. The corresponding figure for the offspring of male carriers is not found to be significantly smaller than that for female carriers, but it cannot be estimated separately since the only patients with carrier fathers are probands. These results may be changed in future when a larger material is available. From the whole material the risk figure for Down’s syndrome is estimated to be 4.1%. The risk for a phenotypically normal child to be a carrier is estimated to be 53.0%. This value does not depend on the sex of the carrier parent.