Dic(21;21) in a Down's syndrome child with an unusual chromosome 9 variant in the mother.
A child with characteristic clinical features of Down's syndrome and raised red cell SOD-1 activity was found to have, in addition to a single chromosome 21, a reverse dicentric tandem translocation of two No 21s with dual NORs and C band regions. The breakpoints on the chromosomes involved in the translocation were at the most distal end of the long arms (21q223). The phenotypically normal mother carried a rare variant of a chromosome 9.
D000328:Adult; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D002904:Chromosomes, Human, 21-22 and Y; D002906:Chromosomes, Human, 6-12 and X; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D010375:Pedigree; D014178:Translocation, Genetic