Transmission of a 13–15/21 translocation in six families

Abstract

SummaryThe genealogical, cytogenetical and blood‐group data available for six families with an inherited translocation between a chromosome of the 13–15 group and chromosome no. 21 are presented. In two families the translocation was transmitted through three generations, in two families it occurred de novo in the carrier parent, and in two families it could not be decided if the translocation was inherited from a further generation or originated in the gametogenesis of generation I. In five families the transmission to a patient with Down's syndrome was maternal, in one family it was paternal. Meiotic studies of a testicular biopsy from a male carrier, the father of a child with Down's syndrome, revealed trivalent formation in diakinesis.

Margareta Mikkelsen

“…The research gave Margareta an opportunity to meet cytogeneticists from all over Europe. She visited laboratories in England in 1962 and met Prof. Lionel Penrose, who published the most important paper of hers in his journal [Mikkelsen, 1966a,b, 1967a]. She visited Prof. Paul Polani's lab and met Dr. Hamerton there.…”

“…Out of her 119 publications before 1978, she published some 20 articles on chromosome 21, wrote some 15 reviews and books on DS, and made 14 more DS surveys. These papers covered the area of etiology, genetic counseling, prenatal diagnosis, and its cost benefit analysis, mortality, cause of death and life‐tables, cytogenetical and genealogical study, incidence study and cytogenetical epidemiology, the effect of parent's age, and the origin of the extra chromosome 21 [Mikkelsen, 1966a,b, 1967a,b, 1969, 1970, 1971a,b; Mikkelsen and Stene, 1970, 1972; Mikkelsen et al, 1976a,b, 1990; Øster et al, 1975].…”