Published online by Cambridge University Press: 01 August 2014
The Authors report the results of a cytogenetical investigation on a group of 140 Down's syndrome patients: nine of them had a translocation (D/G or G/G) and four a mosaic (trisomy 21-22/apparently normal); a mongol girl had 48 chromosomes due to the presence of a small centric chromosome and 21-22 trisomy. All other patients had a regular 21-22 trisomy. Some additional morphological anomalies are described, but interpreted as being expression of the normal human karyotype's variability.