Familial X;Y translocation in a malformed male infant and his mother

Xp;Yq Unbalanced Translocation with Pseudoautosomal Region Aberrations in a Natural Two-Generation Transmission

Translocations involving X and Y chromosomes rarely occur in humans and may affect reproductive function. We investigated an Xp:Yq unbalanced translocation with pseudoautosomal region (PAR) aberrations in a natural two-generation transmission. We report the case of an azoospermic male and his fertile mother without any other abnormal clinical phenotypes, except for short stature. Cytogenetic methods, including karyotyping and fluorescence in situ hybridization (FISH), revealed the translocation. Chromosomal microarray comparative genomic hybridization (array-CGH) was used to investigate the regions of Xp partial deletion and Yq partial duplication. Final chromosome karyotypes in the peripheral blood of the infertile male and his mother were 46,Y,der(X)t(X;Y)(p22.33;q11.22) and 46,X,der(X)t(X;Y)(p22.33;q11.22), respectively. Short-stature-homeobox gene deletion was responsible for the short stature in both subjects. PAR aberrations and AZFc duplication may be a direct genetic risk factor for spermatogenesis. This report further supports the use of routine karyotype analysis, FISH-based technology, and array-CGH analysis to identify derivative chromosomes in a complex rearrangement.

Unique karyotype: mos 46,X,dic(X;Y)(p22.33;p11.32)/ 45,X/45,dic(X;Y)(p22.33;p11.32) in an Egyptian patient with Ovotesticular disorder of sexual development

Ovotesticular disorder of sexual development (OT-DSD) is an unusual form of DSD, characterized by the coexistence of testicular and ovarian tissue in the same individual. In this report, we present clinical, cytogenetic and molecular data of an Egyptian patient with ambiguous genitalia and OT-DSD, who had a unique karyotype comprising 3 different cell lines: mos 46,X,dic(X;Y)(p22.33;p11.32)/45,X/ 45,dic(X;Y)(p22.33;p11.32). This mosaic karyotype probably represents 2 different events: abnormal recombination between the X and Y chromosomes during paternal meiosis and postzygotic abnormality in mitotic segregation of the dic(X;Y) chromosome, resulting in a mosaic karyotype. The presence of the sex-determining region Y (SRY) gene explains the development of testicular tissue. On the other hand, other factors, including the presence of a 45,X cell line, partial SRY deletion, X inactivation pattern, and position effect, could be contributed to genital ambiguity. Explanation of the patient's phenotype in relation to the genotype is discussed with a literature review. We conclude that FISH analysis with X- and Y-specific probes and molecular analysis of the SRY gene are highly recommended and allow accurate diagnosis for optimal management of cases with ambiguous genitalia.

Clinical value of PTEN in patients with superficial bladder cancer

INTRODUCTION

Frequent mutations or deletions of PTEN (phosphatase and tensin homolog deleted on chromosome 10) are reported in bladder cancer, while there are few studies which evaluated PTEN as a clinical prognostic parameter of superficial bladder cancer. We prospectively evaluated PTEN expression in patients with superficial bladder cancer by immunohistochemical staining and defined the value of PTEN mutations in predicting tumor behavior of superficial bladder cancer.

MATERIALS AND METHODS

A total of 190 patients were enrolled in this study. All of the patients underwent transurethral resection of bladder tumor and had superficial tumors. All pathologic materials used in this study were obtained from transurethral resection of bladder tumor. Immunohistochemical stainings were performed. The immunohistochemical staining intensity was judged to be either normal or reduced compared with the PTEN protein expression of positive and negative controls. Disappearance of more than 50% stained cytoplasmic granules was defined as reduced PTEN expression.

RESULTS

The alteration of PTEN expression was significantly different according to tumor stage and grade (p = 0.03, p = 0.048), especially high in carcinoma in situ. However, PTEN expression was not significantly correlated with disease recurrence, progression and recurrence- or progression-free survival.

CONCLUSIONS

Reduced PTEN expression relates to aggressiveness of bladder tumors but seems not to have enough specificity for clinical use in the management of superficial bladder cancer.

FISH deletion mapping defines a single location for the Y chromosome stature gene, GCY

At least 1 in 1000 males lacks part of the long arm of the Y chromosome. This chromosomal aberration is often associated with short stature and infertility. Deletion mapping and genotype-phenotype analysis have previously defined two non-overlapping critical regions for growth controlling gene(s), GCY(s), on the euchromatic portion of the Y chromosome long arm. These initial mapping assignments were based on the analysis of patients carrying a pure 46,XYq- karyotype as defined by classical cytogenetic karyotyping. Four genes have been assigned to the distal one of the two critical regions. To determine whether one or both of these two critical regions harbours GCY and whether one of the four genes assigned to the distal region is involved in determination of stature, nine adult patients with Yq chromosomal abnormalities were studied in detail. By PCR and FISH analysis, we showed that all patients with a previously defined pure 46,XYq- karyotype are actually mosaics with cells containing an idic(Y) or ring(Y) chromosome in association with 45,X0 cells. This leads us to conclude that (1) FISH is an absolute prerequisite for the correct identification of Y chromosomal rearrangements and (2) only patients with interstitial Y deletions are reliable predictors for the physical location of stature gene(s) on Yq. Our molecular analyses of chromosomes from patients with interstitial Yq deletions finally establishes the proximal interval between markers DYZ3 and DYS11 as the only GCY critical interval. No functional gene has so far been identified in this region adjacent to the centromere.

Phenotype/karyotype correlations of Y chromosome aneuploidy with emphasis on structural aberrations in postnatally diagnosed cases

Over 600 cases with a Y aneuploidy (other than non-mosaic 47,XYY) were reviewed for phenotype/karyotype correlations. Except for 93 prenatally diagnosed cases of mosaicism 45,X/46,XY (79 cases), 45,X/47,XYY (8 cases), and 45,X/46,XY/47,XYY (6 cases), all other cases were ascertained postnatally. Special emphasis was placed on structural abnormalities. This review includes 11 cases of 46,XYp-; 90 cases of 46,XYq- (52 cases non-mosaic; 38 cases 45,X mosaic); 34 cases of 46,X,r(Y) (9 cases non-mosaic and 25 cases 45,X mosaic); 8 cases of 46,X,i(Yp) (4 non-mosaic and 4 mosaic with 45,X); 12 cases of 46,X,i(Yq) (7 non-mosaic and 5 mosaic); 44 cases of 46,X,idic(Yq); 80 cases of 46,X, idic(Yp) (74 cases had breakpoints at Yq11 and 6 cases had breakpoints at Yq12); 130 cases of Y/autosome translocations (50 cases with a Y/A reciprocal translocation, 20 cases of Y/A translocation in 45,X males, 60 cases of Y/DP or Y/Gp translocations); 52 cases of Y/X translocations [47 cases with der(X); 4 cases with der(Y), and 1 case with 45,X with a der(X)], 7 cases of Y/Y translocations; 151 postnatally diagnosed cases of 45,X/46,XY; 14 postnatally diagnosed cases of 45,X/47,XYY; 18 cases of 45,X/46,XY/47,XYY; and 93 aforementioned prenatally diagnosed cases with a 45,X cell line. It is clear that in the absence of a 45,X cell line, the presence of an entire Yp or a region of it including SRY would lead to a male phenotype in an individual with a Y aneuploidy, whereas the lack of Yp invariably leads to a female phenotype with typical or atypical Ullrich-Turner syndrome (UTS). Once there is a 45,X cell line, regardless of whether there is Yp, Yq, or both Yp and Yq, or even a free Y chromosome in other cell line, there is an increased chance for that individual to be a phenotypic female with UTS manifestations or to have ambiguous external genitalia. This review once again shows a major difference in reported phenotypes between postnatally and prenatally diagnosed cases of 45,X/46,XY, 45,X/47,XYY, and 45,X/46,XY/47,XYY mosaicism. It appears that ascertainment bias can explain the fact that all known patients with postnatal diagnosis are phenotypically abnormal, while over 90% of prenatally diagnosed cases are reported to have a normal male phenotype. Further elucidation of major Y genes and their clinical significance can be expected in the rapidly expanding gene mapping projects. More, consequently better, phenotype/karyotype correlations can be anticipated at both the cytogenetic and the molecular level.