Cytogenetic analysis of patients with primary amenorrhea in Eastern India

Clinical profile and cytogenetic correlations in females with primary amenorrhea

OBJECTIVE

This study was conducted to investigate chromosomal abnormalities and their correlations with clinical and radiological findings in females with primary amenorrhea (PA).

METHODS

Detailed forms were recorded for 470 females, including the construction of three-generation pedigrees. Peripheral venous blood was drawn, with informed consent, for cytogenetic analysis.

RESULTS

An abnormal karyotype was found in 16.38% of participants. The incidence of structural abnormalities (6.8%) exceeded that of numerical abnormalities (6.15%). Turner syndrome represented 45% of all numerical abnormalities. Furthermore, the Y chromosome was detected in 5% of females with PA. Among the structural chromosomal abnormalities detected (n=32) were mosaicism (25%), deletions (12.5%), isochromosomes (18.75%), fragile sites (3.12%), derivatives (3.12%), marker chromosomes (3.12%), and normal variants (29.125%). An examination of secondary sexual characteristics revealed that 29.6% of females had a complete absence of breast development, 29.78% lacked pubic hair, and 36.88% exhibited no axillary hair development. Radiological findings revealed that 51.22% of females had a hypoplastic uterus and 26.66% had a completely absent uterus. Abnormal ovarian development, such as the complete absence of both ovaries, absence of one ovary, one absent and other streak, or both streak ovaries, was observed in 69.47% of females with PA. Additionally 43.1%, 36.1%, 67.4%, and 8% of females had elevated levels of serum follicle-stimulating hormone, luteinizing hormone, thyroid-stimulating hormone, and prolactin, respectively.

CONCLUSION

This study underscores the importance of karyotyping as a fundamental diagnostic tool for assessing PA. The cytogenetic correlation with these profiles will aid in genetic counseling and further management of the condition.

Cytogenetic screening of chromosomal abnormalities and genetic analysis of FSH receptor Ala307Thr and Ser680Asn genes in amenorrheic patients

Objective

Amenorrhea is a rare reproductive medical condition defined by the absence of menstruation during puberty or later life. This study aims to establish the frequency and pattern of chromosomal abnormalities (CA) in both primary amenorrhea (PA) and secondary amenorrhea (SA), and further to detect the genetic changes in exon 10 at nucleotide positions 919 and 2039 of the genotypes Thr307Ala, and Asn680Ser, respectively.

Design settings and patients

This cross-sectional study was conducted on a sample of seventy amenorrhoeic women according to the Helsinki declaration rules of medical ethics, as divided into 40 (57.14%) with PA and 30 (42.86%) with SA, and 30 healthy women with normal menstruation as the control. The chromosomal karyotyping was performed according to the ISCN, 2020. PCR products were submitted to RFLP and Sanger sequencing for women with normal karyotype and high FSH serum levels.

Results

The classical Turner Syndrome was the most common CA in PA, followed by isochromosome X [46, Xi(X)(q10)], mosaicism of Turner and isochromosome X [45, X /46, Xi(X)(q10)], sex reversal (46, XY) and (46, XX,-3,+der3,-19,del 19 p). Abnormal SA cases were characterized by mosaicism Turner syndrome (45,X/46,XX) and (46,XX,-3,+der3,X,+derX). The homozygous genotypes AA and GG of Ala307Thr (rs6165) in the FSHR gene are most common in PA, while the homozygous genotype AA is more common in SA. GG and AG genotypes of Ser680Asn (rs6166) are more frequent in Iraqi patients with PA and SA compared to the healthy control women. Both PCR-RFLP and Sanger sequencing indicated a marked matching between genotypes.

Conclusions

The study emphasizes the need for cytogenetic analysis to determine the genetic basis of PA and SA. Further, genotyping for women with normal karyotype and high FSH serum concentrations via PCR-RFLP should be considered for the precise diagnosis and development of appropriate management of and counselling for these patients.

Comprehensive molecular analysis identifies eight novel variants in XY females with disorders of sex development

Disorders of sex development (DSD) are a group of clinical conditions with variable presentation and genetic background. Females with or without development of secondary sexual characters and presenting with primary amenorrhea (PA) and a 46,XY karyotype are one of the classified groups in DSD. In this study, we aimed to determine the genetic mutations in 25 females with PA and a 46,XY karyotype to show correlations with their phenotypes. Routine Sanger sequencing with candidate genes like SRY, AR, SRD5A2, and SF1, which are mainly responsible for 46,XY DSD in adolescent females, was performed. In a cohort of 25 patients of PA with 46,XY DSD, where routine Sanger sequencing failed to detect the mutations, next-generation sequencing of a targeted gene panel with 81 genes was used for the molecular diagnosis. The targeted sequencing identified a total of 21 mutations including 8 novel variants in 20 out of 25 patients with DSD. The most frequently identified mutations in our series were in AR (36%), followed by SRD5A2 (20%), SF1 (12%), DHX37 (4%), HSD17B3 (4%), and DMRT2 (4%). We could not find any mutation in the DSD-related genes in five (20%) patients due to complex molecular mechanisms in 46,XY DSD, highlighting the possibility of new DSD genes which are yet to be discovered in these disorders. In conclusion, genetic testing, including cytogenetics and molecular genetics, is important for the diagnosis and management of 46,XY DSD cases.

Heterochromatin extension: a possible cytogenetic fate of primary amenorrhea along with normal karyotype

Primary amenorrhoea (PA) is considered to be one of the challenging and taxing problems for the gynaecologist. Previous studies suggested that different numerical and structural chromosome abnormalities are associated with this. Heterochromatin polymorphisms are considered to be normal variant but considering the recent research on crucial cellular effects of heterochromatin, we have aimed to find out the prevalence of heteromorphism along with other standard chromosomal abnormalities. This was an observational study which was conducted in Diamond Harbour Govt. Medical College and Hospital, West Bengal during March 2019-February 2021. Clinical features of 178 patients were noted and peripheral venous blood was taken following informed consent. This comprehensive study reveals that there are 10.11% of the females among 178 females having a heterochromatin extension which is significantly high. We hence suggest that heteromorphism may be associated with ovarian dysfunction leading to amenorrhoea as the region of heterochromatin acts as a key part in chromosome structure, histone modification and gene regulation. Analysis at the molecular level may be needed to unveil any relationship between heteromorphism and PA. Impact StatementWhat is already known on this subject? Primary amenorrhoea (PA) is a menstrual abnormality found in females with the prevalence of 1-3%. It may be associated with different types of numerical and structural chromosomal anomalies. Among them Turner's syndrome (pure and in variant form) is the commonest chromosomal aberration associated with PA. Some patients with PA are found to have a normal karyotype with heterochromatin extension on the large arm (q) of either chromosome 9 or chromosome 16. Chromosomal polymorphism with increase in heterochromatin region consists of highly repetitive sequences of satellite DNA, which normally does not encode any protein and thus considered to be a normal variant.What do the results of this study add? This comprehensive study reveals that there are 10.11% of the females among 178 females having a heterochromatin extension which is significantly high. PA and certain association of phenotypical stigmata like short stature in these patients with heterochromatin extension can be explained on the basis of histone modification and gene regulation by heterochromatin.What are the implications of these findings for clinical practice and/or further research? We will be able to know about involved transcription factors those are responsible for the histone modification directly linked to the heterochromatin extension by further molecular study. That will definitely help to find out the reason for PA as well as implementation of gene therapy in these cases.

Cytogenetic Studies in Primary Amenorrhoea Cases

Background:

Amenorrhoea is considered a kind of menstrual disorder in a woman of reproductive age. It is a symptom with many potential causes such as an abnormality in the hypothalamic–pituitary–ovarian axis, anatomical abnormalities of the genital tract or functional causes.

Aims:

In this study, we aimed to investigate chromosomal abnormalities in patients presenting with primary amenorrhoea.

Study Setting and Design:

This study was conducted in the medical genetic laboratory.

Materials and Methods:

Chromosomal analysis was carried out in 134 cases that were referred to the human genetic laboratory from 2010 to 2017, employing (GTG) Giemsa banding.

Statistical Analysis:

Statistical analyses were carried out by Microsoft Office Excel (2019).

Results:

The karyotype results revealed 77.6% (n = 104) with normal chromosome composition while 22.38% (n = 30) showed chromosomal abnormalities. Among the patients with abnormal chromosome constituents, 53.54% exhibited numerical aberration and 46.66% showed structural abnormalities.

Conclusion:

The present study has emphasised that karyotyping is one of the fundamental investigations in the evaluation of primary amenorrhoea.

Cytogenetic Study of Patients with Primary Amenorrhea in the Northeast of Iran

BACKGROUND & OBJECTIVE

Primary amenorrhea refers to the absence of menstruation in females of reproductive by age 16 when the development of secondary sexual characteristics is evident (breast development, pubic hair) or by age 14 when there are no secondary sexual characteristics are present. Primary amenorrhea can occur in several quite different reasons. Common hormonal causes of primary amenorrhea include constitutional delay, hypothalamic or pituitary disorders, chronic systemic disease, and primary ovarian insufficiency, some endocrine gland disorders, and other causes. Previous studies suggested that chromosomal abnormality is the second most common cause of amenorrhea. This report aims to measure the prevalence of the chromosomal abnormality in primary amenorrhea (PA) patients in the northeast of Iran.

METHODS

Chromosomal study was carried out on 200 patients with clinical features. The standard method for culturing peripheral venous blood lymphocyte was to prepare metaphase chromosomes and perform routine GTG band analysis.

RESULTS

The results revealed that 71% of PA had normal female karyotype (46,XX) and 29% showed different chromosomal abnormalities. The chromosomal abnormalities can be categorized into seven primary groups with or without mosaicism. 1- The most common karyotype was X chromosome aneuploidy (10.5%, n=21), 2- Male karyotype with or without structural abnormality of Y chromosome (5.5 %, n=11), 3- Mosaicism of turner karyotype and structural anomalies of X chromosome (4%, n=8), 4- Structural anomalies of the X chromosome (3.5%, n=7), 5- Mosaicism of turner karyotype and normal karyotype (3%, n=6), 6- Mosaicism of turner karyotype and male karyotype (1.5%, n=3) and 7- Super female karyotype (1%, n=2).

CONCLUSION

The present study has emphasized that early cytogenetic and timely investigation can be necessary for the evaluation of primary amenorrhea.

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.

Identification of the first homozygous POLG mutation causing non-syndromic ovarian dysfunction

OBJECTIVE

To investigate the genetic cause of non-syndromic ovarian dysfunction in a patient from a consanguineous family.

METHODS

This study examined a patient with irregular menstrual cycles and abnormal oocytes. The patient had undergone irregular hormone replacement therapy over 3 years to adjust the menstrual cycle and improve ovarian function. Prior to ovarian stimulation in our hospital, 3 months of androgen and regular hormone therapy were used as an intervention method. No follicular development was detected in the subsequent three cycles using letrozole treatment. The patient then received a constantly adjusted dose of menotropins, but produced only one oocyte.

RESULTS

Whole-exome sequencing analysis identified the first homozygous POLG mutation (c.2890C > T; p.R964C) associated with ovarian dysfunction. Sanger sequencing was used to validate. In silico analysis suggested that the p.R964C mutation was pathogenic. Conservation analysis demonstrated that R964 was an important site for the DNA polymerase function of POLG.

CONCLUSIONS

Biallelic mutations in POLG may be associated with ovarian dysfunction. This study has improved our understanding of POLG-related genetic mutations in ovarian dysfunction, and the mode of inheritance of certain sequence variants. This information will assist genetic counseling and precision medicine in the future.