TRISOMY OF THE SHORT STATURE HOMEOBOX-CONTAINING GENE (SHOX) DUE TO DUPLICATION-DELETION OF THE X CHOMOSOME. CLINICAL IMPLICATIONS ON THE STATURE.

GRACIELA DEL REY; HÉCTOR JASPER; SONIA VIVIANA BENGOLEA; ADRIANA BOYWITT; RODOLFO DE BELLIS.; JUAN JORGE HEINRICH

HORMONE RESEARCH

KARGER

Lugar: Switzerland; Año: 2010

0301-0163

Abstract Aims: To report on two patients with abnormal stature and different phenotypes but whose karyotypes, by conventional cytogenetic studies and fluorescence in situ hybridization analysis (FISH) present one similar structurally abnormal X-chromosome. FISH strongly suggested the presence of two copies of SHOX gene in the der(X) chromosome. Patients and Results: Patient 1 is a teenager girl with tall stature, behavioural disturbances and normal pubertal development. The abnormal X-chromosome was present in all cells studied. Parents´s karyotypes were normal. Patient 2 is a girl with gonadal dysgenesis, mild Turner syndrome phenotype and short stature. The karyotype was a mosaic 45,X/46,X,r(X) and der(X) chromosome present in most  metaphases of the cell lines. Parents´s karyotypes were normal. Nearly all duplication of Xp and partial deletion of the long arm (Xq) from Xq27 or Xq21 to Xqter, in the first and the second cases respectively, were observed. In both patients, duplication of Xp translocated to deleted Xq occured leading to a triplication of the pseudoautosomal region 1 (PAR1) where the SHOX gene is located (Xp22.3). Conclusions: We propose that in some cases resulting trisomic for SHOX gene, the effect of overdosage per se may affect the stature, even in those patients with preserved ovarian function (case 1), and that estrogen deprivation may not always be a contributor for tall stature (case 2).