NORMAL GROWTH AND NORMALIZATION OF HYPERGONADOTROPIC HYPOGONADISM IN ATYPICAL TURNER SYNDROME (45,X 46,XX/47,XXX) - CORRELATION OF BODY HEIGHT WITH DISTRIBUTION OF CELL-LINES/

A comparison has been made of a case with 45,X/46,XX/ 47,XXX mosaicism with some 50 cases in the literature. A significant positive correlat ion was found between height standard deviation scores of mosaic patie nts from the literature and the frequency of cells with a normal chrom osome constitution (n = 21, r(s) = 0.552, P < 0.01). In contrast, a si gnificant negative correlation was seen between body height and the fr equency of cells with a 45,X constitution (n = 21, r(s) = -0.594, P < 0.01). There was no significant cell-elation of height standard deviat ion score with the 47,XXX cell line (n = 21, r(s) = -0.353). A patient with a rare chromosomal mosaicism (45,X/46,XX/ 47,XXX) is described. The diagnosis was first made by chromosome analysis in amniotic cells. The patient showed no symptoms suggestive of Turner syndrome and grow th followed the 75th height percentile. Basal and gonadotropin-releasi ng hormone stimulated gonadotropin levels normalized after age 4.8 yea rs and did not subsequently return to hypergonadotropic levels. In blo od lymphocytes, there was an increase in the frequency of cells with a normal chromosome constitution over 9 years. This in vivo cell select ion is discussed. Chromosome analysis in skin fibroblasts showed the s ame triple mosaicism with a similar distribution of cell lines as in b lood lymphocytes. In conclusion, statistical evidence was demonstrated that the severity of short stature is correlated with the distributio n of cell lines in 45,X/46,XX/47,XXX mosaicism. This finding is of imp ortance for the genetic counselling in cases of prenatal diagnosis of mosaic Turner syndrome.