Diagnosing of chromosome abnormalities in Denmark

Abstract
A survey of how frequent chromosome abnormalities are diagnosed in Denmark prenatally as well as postnatally compared with the expected incidence in an 11‐year period 1970–1980 has been made from the Danish Cytogenetic Central Register. Ten percent of the expected number of Klinefelter's syndrome, 41% of Turner's syndrome and 10% of other sex chromosome abnormalities in children born between 1970 and 1980 have been diagnosed until January 1, 1983. The total frequency of diagnosed cases with sex chromosome abnormalities is 13% of the expected number. Induced abortion was made in 62% of the cases with sex chromosome abnormalities diagnosed prenatally. Ninety percent of all cases with Down's syndrome were diagnosed by chromosome examination, and 10% were diagnosed prenatally and aborted. During the last part of the period from 1977–1980 this had increased to 20%. Thirty‐seven percent of cases with other chromosome abnormalities were diagnosed. Among the expected 4,396 children with chromosome abnormalities to be born between 1970 and 1980, a total of 39% were diagnosed postnatally until January 1, 1983, and 10% were diagnosed prenatally. It is concluded that there is a great need for training consultants in clinical genetics, expansion and further decentralization of cytogenetic service with more cytogenetic laboratories and employment of clinical geneticists in all 14 Danish counties.