Del(X)(p21.1) in a mother and two daughters: genotype-phenotype correlation of Turner features

We report a mother and two daughters with partial Xp monosomy. Clinical ass essment for Turner phenotype revealed that the three females manifested low -normal to mild short stature (-1.6 to approximately -2.3 SD) and variable degrees of skeletal features, such as cubitus valgus, short 4th matacarpals , and Madelung deformity, but no soft tissue or visceral anomalies or gonad al dysfunction. Cytogenetic studies for lymphocytes showed that the karyoty pe was 15,X[3]/46,X,del/(X)(p2 1.1)[27] in the mother and non-mosaic 46,X,d el(X)(p21.1) in the two daughters. Fluorescence in situ hybridization and m icrosatellite analyses for 19 loci/regions on the X chromosome demonstrated that the del(Xp) chromosome was missing SHOX and had the breakpoint betwee n DMD and CYBB. The results are consistent with the recently proposed notio n that haploinsufficiency of SHOX results in not only short stature, but al so Turner skeletal features in association with maturational effects of gon adal estrogens. The lack of soft tissue or visceral anomalies suggests the presence of the putative lymphogenic gene on the del(Xp) chromosome: the pr eservation of ovarian function appears to be compatible with meiotic pairin g failure being relatively mild.