Isodicentric Y (p11.32) chromosome in an infant with mixed gonadal dysgenesis

Clinical, cytogenetic, and molecular findings of isodicentric Y chromosomes

Background

Isodicentric Y chromosomes [idic(Y)] are one of the most common structural abnormalities of the Y chromosome. The prenatal diagnosis of isodicentric Y chromosomes is of vital importance, and the postnatal phenotypes vary widely. Therefore, we present six patients prenatally diagnosed with isodicentric Y chromosomes and review the literature concerning the genotype-phenotype correlations.

Method

The clinical materials of six patients were obtained. Cytogenetic and molecular approaches were carried out for these six patients.

Results

Isodicentric Y chromosomes were found in all sixpatients. Among them, four patients presented with a mosaic 45,X karyotype, one patient had a 46,XY cell line, and one patient was nonmosaic. Five of these six isodicentric Y chromosomes had a breakpoint in Yq11.2, and the other had a breakpoint in Yp11.3. The molecular analysis demonstrated different duplications and deletions of the Y chromosome. Finally, three patients chose to terminate the pregnancy, two patients gave birth to normal-appearing males, and one patient was lost to follow-up.

Conclusion

The incorporation of multiple cytogenetic and molecular techniques would offer a more comprehensive understanding of this structural chromosomal abnormality for genetic counselling.

Short Stature on a Boy: Mosaicism with an Isodicentric Y Chromosome

Mosaicism brings great variability into the clinical expression of numerical and structural chromosomal abnormalities. The phenotypic variability of 45,X/46,XY mosaicism extends from Turner syndrome to apparently physically normal males. We present a case of a 14-year-old adolescent with short stature and delayed puberty, who was admitted in a Paediatric Endocrinology outpatient clinic. After a careful investigation, he was found to have a 45,X/46,X,idic(Y)(p11.32) mosaicism. This case report emphasizes the wide range of etiologies that can be involved in short stature and that chromosomal study is an important tool when firstly approaching males with short stature, avoiding unnecessary tests. There is an important clinical need for gonadal follow-up in this situation and for support in the decision about sex of rearing and sex orientation, when justifiable.

Clinical and cytogenomic studies in a case of infertility associated with a nonmosaic dicentric Y chromosome

In this study, a short stature male with infertility is reported. Semen analysis and serum concentrations of FSH, LH, T and PRL were estimated. Chromosome analysis was performed on lymphocytes obtained from both the male and his parents. Cytogenomic studies were performed by fluorescent in situ hybridisation and the CytoScan(™)  HD array analysis to detect Y chromosomal rearrangements and copy number mutations. Semen analysis showed severe oligozoospermia. Numerous spermatogenic cells were observed in the semen, and approximately 60% of the cells examined in semen were primary spermatocytes, showing spermatogenic arrest at the primary spermatocyte level. Cytogenomic studies of blood revealed his karyotype which was 46,X,i(Y) (p11.32) (Yqter→Yp11.32::Yp11.32→Yqter).ish (DYZ3++, SRY++, SHOX-). array (PLCXD1→SHOX) ×1,(SRY →GOLGA2P3Y)×2, (DHRSX→ ASMT, SPRY3 →IL9R)×3. The rearrangement Y chromosome is de novo. This is the first case reported with a nonmosaic 46,X, i (Y) (p11.32), which will be useful to estimate the infertility phenotype-molecular karyotype correlation. Haploinsufficiency of short stature homeobox-containing gene is primarily responsible for the short stature. Aberrations in pseudoautosomal region 1 on the rearranged Y chromosome may result in the deficiency of X-Y pairing or recombination, ultimately lead to the spermatogenic failure.

Laparoscopic diagnosis and treatment of a phenotypic girl with mosaic 45,XO/46,X,idic(Y) mixed gonadal dysgenesis

We report our experience with laparoscopic gonadal biopsy and gonadectomy for a girl with a dicentric Y chromosome in mixed gonadal dysgenesis (MGD). A 4-year-old phenotypic girl was referred to our hospital because of slight enlargement of the clitoris. Fluorescence in situ hybridization analysis with Y chromosome-specific probes showed a karyotype with 45,XO/46,X,+idic(Y)(p11.32) and presence of the sex-determining region Y sequence. The pathologic finding by frozen section technique using laparoscopic biopsy specimens during the operation demonstrated a left streak gonad and right testis, and she was diagnosed with MGD. Finally, we performed laparoscopic bilateral gonadectomy. Laparoscopic management is a good approach for patients with sexual development disorders, including MGD because it provides minimally invasive surgery for children and enables all necessary procedures, including evaluation, biopsy, and gonadectomy, for diagnosis and treatment.

Cytogenetic and molecular characterization of the derivative Y chromosome: a case study of an azoospermic patient

The success of infertility treatment depends on the underlying cause and severity of the infertility problem. The current report addresses the complex genotype-phenotype interactions in an azoospermic man. Cytogenetic, molecular cytogenetic and molecular genetic studies indicated the derivative monocentric Y chromosome with duplication of Yp11 (including SRY gene) and partial deletion of Yq11 (including azoospermia factor - AZFb-c regions) as the most probable cause of the severe testicular failure. Our study emphasizes the importance of detailed genetic analysis in male infertility evaluation and helps to estimate the outcome of infertility treatment.

Mixed gonadal dysgenesis associated with an isodicentric Y chromosome

A szerzők egy izodicentrikus Y-kromoszómát tartalmazó kariotípusú kevert gonáddiszgenezises esetükről számolnak be, melyet fiatal csecsemőkorban diagnosztizáltak. Szükségesnek tartják a perineoscrotalis hypospadiasissal és az egy- vagy kétoldali hereleszállás zavarával született újszülöttek speciális kivizsgálását közvetlenül a szülés után. A részletes kivizsgálás eredménye biztosítja a korrekt nemi besorolást és a diszgenetikus gonád malignus elfajulásának megelőzését.