Duplication deficiency of an X-chromosome with and without 45,X mosaicism in three girls. Cytogenetic, clinical, and hormonal findings.

In three girls, aged 14, 15 and 16 years, the chromosome analysis revealed a morphologically abnormal, enlarged X-chromosome resembling in size and centromere position the chromosome no. 2. The translocation points were different in all three cases. The Barr-bodies were enlarged. In two girls a 45,X mosaicism (25% and 10%) was found in lymphocyte cultures. The length at birth was 43, 47 and 48 cm, and none of the girls was born before term. The main clinical abnormalities in all three cases were a marked growth retardation, slight morphological dysplasias, lack of sexual development and social immaturity. GH and cortisol secretion during an insulin tolerance test were normal. LH and FSH were elevated and showed an exaggerated reaction on LH-RH. Oestrogens were low normal and androgens within the normal range. At laparatomy the gonads were found to be streak gonads. For two girls cell cultures of gonadal tissue were set up, the chromosome findings of which corresponded to those of the lymphocyte cultures. The abnormality of the gonosomes reported here seems to represent a special form of gonadal dysgenesis. Although the translocation points were different in the three patients and one had no mosaic, while the other two showed 45,X/46,XX mosaicism, the clinical and hormonal findings were nearly the same for all three girls.