Trisomy in Mother and Child

Reproduction in Human Autosomal Trisomics

“…When one examines chromosome counts on mongol mother and offspring, 5 offspring of 5 mothers were available to our knowl¬ edge 6,8,11,13,15 (Table 5). All 5 mongol mothers have 47 chromosomes.…”

Down's Syndrome (mongolism): The heritable aspects.

“…The occurrence of the extra small chromosome was soon confirmed by Jacobs,Baikie,Court Brown,and Strong (19S9) who had independently observed the same phenomenon. During the succeeding years numerous further studies of patients with Down's syndrome affirmed the characteristic number of 47, the extra small chromosome being designated as number 21 (Book, Fraccaro, & Lindsten, 1959;German & Beam, 1960;Hanhart, Delhanty, & Penrose, 1961;Lejeune, Gautier, & Turpin, 19S9b;Makino, Honda, & Mitani, 1962;Miller, Breg, Schmickel, & Tretter, 1961). The cells of such individuals then contain three, instead of the 1 Prior to the above noted methodological advances the human diploid number was believed to be 48. normal two, chromosomes number 21 and persons with this abnormality (trisomy number 21) are referred to as 21-trisomics.…”