Chromosomes and the gynecologist

Study of frequency and types of chromosomal abnormalities in phenotypically female patients with amenorrhea in Eastern Indian population

AIM

This comprehensive review article aims to comprehend the frequency and prevalence of chromosomal abnormalities in both primary amenorrhea (PA) and secondary amenorrhea (SA) cases and correlating it with their phenotypes, clinical features and hormonal profiles.

METHODS

Research publications on prevalence of chromosomal abnormalities in both PA and SA cases worldwide and its etiology, clinical features, hormonal profiles; their correlation with chromosomal profiles were searched for on the internet, including general search engines and respective scientific sites. Only published, relevant and authentic data conducted on phenotypically female patients were considered. Another aspect of amenorrhea occurs due to several clinical conditions apart from cytogenetic viewpoint were not considered or discussed in detail.

RESULTS

As literature study suggests; considering various etiology of amenorrhea counting anatomic defect of the hypothalamus or genetic defect, and various acquired causes of chromosomal anomalies contribute to be one of the major etiologies of both PA and SA; ranging from 15.9% to 63.3% in case of PA and from 3.9% to 44.4% in case of SA. In spite of the presence of any other factors responsible condition, the genetic factors need to be emphasized, which might include single gene disorders or chromosomal disorders. Individuals with chromosomal anomalies reported a wide range of abnormalities in phenotypes, as well as in other clinical features and hormonal profiles.

CONCLUSION

This comprehensive review is the first structured review article that encompasses the cytogenetic profile of the amenorrhea cases and correlating it with their phenotypes, clinical features and hormonal profiles from Eastern India.

Molecular Cytogenetic Characterization of a Non-Robertsonian Dicentric Chromosome 14;19 Identified in a Girl with Short Stature and Amenorrhea

We report a 16-year-old girl who presented with short stature and amenorrhea. Initially the cytogenetic analysis showed the presence of a mosaic non-Robertsonian dicentric chromosome involving chromosomes 14 and 19. Subsequent molecular cytogenetic analysis by fluorescence in situ hybridization (FISH) using whole chromosome paints, centromeric probes, as well as gene specific probes confirmed the dicentric nature of the derivative chromosome and indicated that the rearrangement involved the short arms of both of these chromosomes. Furthermore, we also determined that the chromosome 19p13.3 breakpoint occurred within the terminal 1 Mb region. This is the first report of a mosaic non-Robertsonian dicentric chromosome involving chromosomes 14 and 19 with the karyotype determined as 45,XX,dic(14;19)(p11.2;p13.3)[35]/46,XX[15], and we suggest that the chromosome rearrangement could be the cause of clinical phenotype.

Frequency of abnormal karyotypes in relation to the ascertainment method in females referred for suspected sex chromosome abnormality

Cytogenetic investigation was carried out on 231 female patients referred for suspected sex chromosome abnormality. Cases were classified into five groups according to reason for referral and chromosome abnormality frequency was estimated. The overall frequency of abnormal karyotypes was 38.5%. The rate of positive identification of chromosome abnormality ranges from 0 in patients with secondary amenorrhoea to 80% in those with Turner phenotype. Our data demonstrate that the indications for referral of female patients with suspected sex chromosome abnormality are not only primary amenorrhoea alone or short stature and primary amenorrhoea without Turner stigmata, but also short stature of unknown etiology without any additional anomaly during childhood.

Cytogenic investigation of 103 patients with primary or secondary amenorrhea

Cytogenetic investigations were carried out on 103 women presenting with either primary (n = 88) or secondary (n = 15) amenorrhea. A sex chromosome anomaly was found in 26% and 33% of these patients, respectively. Other studies on women with primary amenorrhea have found a similar or even higher percentage of patients with an abnormal karyotype. It is therefore suggested that all women with absence of menstruation after the age of 16 years should be investigated cytogenetically. The surprisingly high percentage of pathological karyotypes among the secondary amenorrhea group does indicate that sex chromosome anomalies cannot be ruled out in women who have had apparently normal ovarian function for at least some time, and therefore more patients from this group should be selected for chromosome analysis.

Cytogenetic investigations in 150 cases with complaints of sterility or primary amenorrhea

Cytogenetic investigations were carried out on 150 individuals. Out of these 107 were females and 43 males. Eighty seven of the above (43 males and 44 females) had been referred for sterility. Sixty three patients had primary amenorrhea and had been referred directly to this laboratory by clinicians, having been suspected of genetic abnormalities. Twenty-two cases (14.7%) involved in this study chromosomal abnormalities and seven cases (4.7%) showed chromosomal polymorphism. Of the 107 females (44 sterile and 63 with primary amenorrhea), 11 (10.2%) showed numerical or structural sex chromosomal abnormalities. Five patients (4.67%) showed chromosomal polymorphism (involving the paracentromeric and centromeric regions of chromosomes 1 and 9, double satellites, and giant satellites. Of the 43 males, 11 (25.59%) showed numerical and structural abnormalities. Ten cases were anomalies involving the sex chromosomes. One case of a triple autosomal translocation in an otherwise phenotypically normal azoospermic male was of particular interest. Two cases (4.65%) showed double satellites of the acrocentrics.