Humangenetik 15, 93--95 (1972) © by Springer-Verlag 1972

Different Chromosome Variants of Klinefelter's Syndrome and Plasma Testosterone

J i i~i ~EUWIRTH

3rd Medical Department, Charles University, Praha

LUBOg STXn~A

Research Institute of Endocrinology, Praha

JA~ tCA~OC~

Sexuological Institute, Charles University, Praha, Czechoslovakia

Received February 17, 1972

Summary. We have found that a group of 53 chromatin-positive males consisting of XXY, XX and X Y / X X ¥ individuals had significantly lower average value of plasma testosterone than a group of 82 normal men. A comparison of these different chromosome variants and their plasma testosterone showed distinctly lowest value in males with 46,XX karyotype.

Zusammen/assung. Wir haben gefunden, dal~ eine Grappe yon 53 ehromatinpositiven M/~nnern, bestehend aus einzelnen X X Y , XX und XY/XXY, einen durchschnittlich niedrigeren Wert an Plasmatestosteron hatten als eine Gruppe yon 82 normalen M~nnern. Ein Vergleich yon verschiedenen Chromosomenvarianten und deren Plasmatestosteron zeigte genau den niedrigsten Weft bei M/innern mit 46,XX-Karyotyp.

Prev ious s tudies (Saunwhite et al., 1962; L ipse t t et al., 1965; Moon et a l , 1968; Saba et al., 1969) have shown in a l imi ted n u m b e r of ehromat in-pos i t ive males t h a t t es t i cu la r hormona l a c t i v i t y is mos t ly reduced. The same conclusion was reached b y Paulsen et al. (1968) th rough the examina t ion of 25 chromat in -pos i t ive men. I t is also well known t h a t a p a r t f rom the commones t k a r y o t y p e X X Y a whole va r i e ty of abno rma l sex chromosome complements were descr ibed in Kl inefe l te r ' s syndrome. I n our presen t s t u d y we have t r i ed to find whe ther different chromosome va r i an t s of Kl inefe l te r ' s synd rome are accompan ied b y different levels of p l a sma tes tos te rone in adul ts .

Materials and Methods

The chromosome complements were determined by the peripheral blood culture according to Moorhead st al. (1960) in a group of 53 chromatin-positive men in age from 21 to 45 years. The values of plasma testosterone were determined by the protein-binding method of Horton et al. (1967). A group of 82 well fertile and sexualy potent men aged 21 to 50 years with normal palpatory findings on genitals was used for comparison.

Results

The resul ts are summar ized in the following Table 1. S ta t i s t i ca l analysis has shown t h a t the difference be tween the group of 82 norma l m a n and t h a t of 53 chromat in -pos i t ive ind iv idua l s is h igh ly signif icant ( P < 0.01). The men wi th

94 J. Neuwirth, L. St~rka, and J. 1%aboch:

Table i

Group Chromosome No. of Plasma testosterone complement cases ng/ml =~ S.D.

n

Normal men 46,XY 82 8.90 2.51

Chromatin-positive men whole group 53 5.45 1.73 46,XY/47,XXY 6 5.86 1.06 47,XXY 43 5.67 1.86 46,XX 4 2.56 1.40

Klinefelter's syndrome were found to have distinctly lower average values of plasma testosterone. A comparison of plasma testosterone levels in different chromosome variants of Klinefelter's syndrome showed the lowest value in patients with 46,XX chromosome complement. The difference was significant at 5% level (t-test).

Discussion

Our results coming from the group of 53 chromatin-positive men are in agree- ment with findings of Saunwhite et al. (1962), Paulsen et al. (1968), Moon et al. (1968), Saba et al. (1969) and show that the presence of a supernumerary X chromosome is accompanied by distinctly lowered function of Leydig cells. I t is of interest that the males with a supernumerary Y chromosome have normal plasma testosterone levels (Price and van der Molen, 1970). We consider as a quite remarkable finding that the men with Klinefelter's syndrome and 46,XX chromosome complement showed the lowest value of plasma testosterone in comparison to those with karyotypes 47,XXY and 47,XXY/46,XY. Although the 46,XX chromosome complement markedly reduces the production of testosterone in gonads it seems that it does not influence the sensitivity of target organs. I t is interesting that our 4 men with 46,XX karyotype are married and display adequate sexual activity; 3 of them yielded repeatedly normal quantity of spermatie fluid (more then 2 ml). Our study also would like to be a modest contribution to the problem whether or not males with the karyotype 46,XX form a clinical entity of their own.

For technical assistance we are grateful to Mrs Cesk~ and Miss Kovandov£.

References

Horton, 1~., Kato, T., Sherins, R. : A rapid method for the estimation of testosterone in male plasma. Steroids 10, 245--256 (1967).

Lipsett, M. B., Davis, T. E., Wilson, H., Canfield, C. J. : Testosterone production in chromatin- positive Klinefeiter's syndrome. J. clin. Endocr. 25, 1027--i029 (1965).

Moon, K. H., Osborn, t~. H., Yannone, M. E., Bunge, R. G. : Seminal fl'uetose and hormonal studies in Klinefelter's syndrome. Invest. Uro]. 6, 179--182 (1968).

Moorhead, P. S., Nowell, P. C., Mellman, W. J., Battips, D. M., Hungerford, D. A. : Chromo- some preparation of leukocytes cultured from human peripheral blood. Exp. Cell Res. 20, 613--616 (1960).

Klinefelter's Syndrome and Plasma Testosterone 95

Paulsen, C.A., Gordon, D. L., Carpenter, R.W.: Xlinefelter's syndrome and its variants: a hormonal and chromosomal study. Recent Progr. J:Iormone Res. 24, 321--363 (1968).

Price, W. H., van der Molen, H. J. : Plasma testosterone levels in males with the XY¥ karyo- type. Endocrinology 47, I17--122 (1970).

Saba, P., Gambassi, G., Novi, A. 2VI., Luisi, M. : Electron microscopy of the Leydig cells and hormone assays in Klinefelter's syndrome. Endokrinologie gS, 129--144 (1969).

Saunwhite, W. g., Sandbcrg, A. A., Staubitz, W. J., Jackson, J. E., Xoepf, C. F. : Synthesis of testosterone by subjects with gonadal dysgenesis and X X Y chromosome constitution. J. olin. Endocr. 2~, 989--991 (1962).

Ji~'f Ncuwirth, hi.D. 3rd Medical Department Faculty of 1Vfedieine, Charles University U nemocnice I Praha 2, Czechoslovakia