We report on the transmission of an X chromosome with a deletion of the short arm from a mother with 45,X/46,X,del(X)(p21.2) mosaicism to her daughter with a 46,X,del(X)(p21.2) karyotype. Nevertheless, the potential of karyotype/phenotype correlation is limited in this case because of simultaneous occurrence of small stature with disproportionate short limbs.
The pedigree of the family is given in Figure . The proposita presented first at age 7 years for evaluation of short stature (114 cm, <3rd centile). Broad chest, low hair line, nail hypoplasia, cubitus valgus, vesicoureteral reflux, hypoplasia of the left kidney, dental abnormalities, and mild aortic insufficiency suggested the Ullrich-Turner syndrome. Karyotype analysis in p e r i p h e r a l b l o o d s h o w e d a d e l e t i o n o f X p : 46,Xdel(X)(p21). Menarche occurred at 10 years, followed by oligo-and hypermenorrhea. Gynecological examination at 12 years showed polycystic ovaries with slight fibrosis of the ovarian capsule. Only a few follicles were detected at biopsy. At age 10 years (standing height: 135 cm, 10th centile; sitting height: 80 cm, 97th centile) subtle disproportion between limbs and trunk became evident. Therefore, genetic evaluation was extended. Karyotype analysis was repeated and the breakpoint on the X chromosome (Fig. ) was determined more precisely: 46,Xdel(X)(p21.2). Chromosome painting with a whole chromosome probe of the X chromosome did not indicate an X/autosome translocation. The 40-year-old mother, with a standing height of 142 cm (<3rd centile) and a sitting height of 80.5 cm (3rd centile), experienced menarche at 14 years and had regular menses until hysterectomy at age 37 years. No history of miscarriage was documented. Karyotype analysis in peripheral blood (100 metaphases) showed mosaicism of cells with monosomy of the X chromosome (94%) and cells with a deletion of the short arm of the X (6%): mos45,X/46,X,del(Xp21.2). The 44-year-old father (karyotype: 46,XY), with a height of 166 cm (<3rd centile) and a sitting height of 96.3 cm (75th centile) showed a disproportion between trunk and limb length.