Molecular cytogenetic investigation of two patients with Y chromosome rearrangements and intellectual disability

Sex chromosomes and sex chromosome abnormalities

This article focuses on constitutional sex chromosome abnormalities detected by conventional cytogenetics and fluorescence in situ hybridization. The author discusses the two general classifications of abnormalities: numerical and structural. Also included are descriptions of unique aspects of X and Y chromosomes, technological advances in detection, and future perspectives.

45,X maleness: clinical and cytogenetic features in two patients

45,X maleness is a very rare disorder. We report on 2 new 45,X males aged 9 10/12 and 39 years, respectively. The boy presented for developmental delay, while the man was referred to us because of infertility. Both patients showed short stature (boy -2.29 SDS, man -4.05 SDS) and an unbalanced translocation of Yp, including SRY, onto the long arm of chromosome 10 and short arm of chromosome 14, respectively. The growth pattern of the 2 patients and literature data suggest the presence of a specific growth gene in the pericentrometric region of Yq. In addition, developmental delay in some 45,X males may be related to specific deletion of telomeric autosome regions, but involvement of gene(s) on the Y chromosome may play a role as well. Albeit in the boy inhibin B levels were in the normal range for age, azoospermia was demonstrated in the adult, supporting that infertility is a feature of adult 45,X men with AZFa-c deletion.