American Journal of Medical Genetics 36:366 (1990)

Letter to the Editor

Response to F’ryns et al.: Isochromosome Xq in Klinefelter Syndrome

To the Editor:

I was very interested to hear about the two additional cases of Klinefelter syndrome with an isochromosome Xq, which were published by Kleczkowska et al. in their paper entitled “X-chromosome polysomy in the male.”

Of these two patients, the one having the nonmosaic 47,Xi(X)Y karyotype, does indeed seem to have in- creased height (198 em), although this must be judged in comparison to parents and sib. This observation is con- trary to the lack of height increase found in the seven cases for which height was mentioned among the eight patients whom we reviewed.

The second patient, who had a 47,XXY/48,XXi(Xq)Y mosaicism, does not seem to have a height increase (164.5 cm), but his chromosome composition is too differ- ent to bring conclusive evidence for this evaluation.

Concerning the normal testosterone levels found in our patient, we reported this as an unusual occurrence, not observed in the other patients reviewed and thus not part of what we thought could be characteristic of an i(Xq) Klinefelter syndrome.

Claude-Lise Richer Departement d’Anatomie Faculte de Medecine Universite de Montreal C.P. 6128, Succ. “A” Montreal, Quebec, H3C 357, Canada

Fkceived for publication April 24, 1989.

0 1990 Wiley-Liss, Inc.