THE PREVALENCE OF CHROMOSOMAL ABNORMITIES DIAGNOSED PRENATALLY IN A AN AND POPULATION

THE PREVALENCE OF CHROMOSOMAL ABNORMITIES DIAGNOSED PRENATALLY IN A AN AND POPULATION

Ankita Bhatiya *, Hitesh Shah and Smruti Vaishnav

Smt. L. P. Patel Institute of Medical Laboratory Technology, Karamsad, Anand, Gujarat, India.

ABSTRACT: Background: The most important factor contributing to human genetic problems is chromosomal abnormalities. It is crucial to choose screening tests and diagnostic procedures that are exact, accurate, safe, and able to be conducted during early pregnancy in order to make the best-informed choice possible while taking into account the probable outcomes of pregnancy. Method and Material: In the present prospective study chromosomal analysis was done for various types of suspected 900 referred patients. The patients were referred from mainly Gynaecology hospital Usha Nursing Home and Sat Kaival Hospital, Anand in association with Gene Care Accuris Laboratory, Surat from June 2021 to March 2023. Result: The overall frequency of chromosomal abnormalities was 2.5% (23/900). Out of 23 cytogenetic abnormal patients, numerical abnormalities were found in 21(2.33%) and structural abnormalities we detected in 02(0.22%) patients. The most common autosomal abnormalities were Down’ syndrome 18(2%). Another abnormality was Edward’s Syndrome 03(0.33%). Chromosomal structural disorder occupied 02(0.22%) including robertsonian translocation. Conclusion: To avoid the delivery of foetuses with chromosomal disorders, karyotype screening of amniotic fluid is a crucial strategy. Our results underline the significance of cytogenetic investigations in individuals with signs of prenatal diagnosis because an aberrant finding not only gives patients the option of terminating or continuing their pregnancies but also serves as a foundation for genetic counselling and helps in creating a healthier society.

Keywords: Prenatal diagnosis, Chromosome aberrations, Cytogenetic, Karyotype

INTRODUCTION: The most important factor contributing to human genetic problems is chromosomal abnormalities. Many kinds of chromosomal abnormalities, both structural and numerical, have been clinically suspected of having genetic abnormalities.

To identify chromosomal deletion, translocation, duplication, inversion, and aneuploidy of the autosomes and sex chromosomes, cytogenetic investigation is crucial ¹.

Other issues include the absence of treatment options for chromosomal disorders and false-positive screening tests in sonography and/or maternal serum. It is crucial to choose screening tests and diagnostic procedures that are exact, accurate, safe, and able to be conducted during early pregnancy in order to make the best-informed choice possible while taking into account the probable outcomes of pregnancy in between 2% and 5% of all live births, genetic and congenital abnormalities are reported to occur by the World Health Organisation. In developing nations, these changes are responsible for 50% of all childhood fatalities. Additionally, they are mostly to blame for prenatal and neonatal mortality in underdeveloped nations ². Cytogenetics analysis has grown significantly in importance over the past ten years as a tool for genetic counselling, which deals with the human issues connected to the presence or risk of a genetic disorder in a family and aids in understanding the diagnosis, prognosis, and available management, as well as the genetic basis, likelihood of recurrence, and available options ³. Objective of the present study is to assess the prevalence and kind of chromosomal abnormalities in high-risk pregnancies utilizing karyotype and FISH analysis of amniotic fluid cells.

MATERIAL AND METHODOLOGY: After approval from the institutional ethics committee, a prospective clinical study was conducted at Usha Nursing Home and Sat Kaival Hospital, Anand in association with Gene Care Accuris Laboratory, Surat from June 2021 to March 2023. After diagnostic counselling acquiring family and gestational history. The patients also received comprehensive prenatal diagnosis. Informed written consent was taken. Pregnant women in whom serum screening tests (Double marker & Quadmarker) showed a high fetal risk underwent prenatal testing. Maternal serum screening consisted of tests for the free beta-human chorionic gonadotrophin (free β-hCG) and pregnancy-associated plasma protein A (PAPP-A) in the first trimester, and in the second trimester the Quadmarker test for alpha-fetoprotein (AFP), β-hCG, and unconjugated estriol (uE3) and Inhibin A. PRISCA software was used for prenatal screening and calculated the relative multiples of median (MoM) and risk values. Gynaecologist was responsible for ordering all the investigation. Ultrasound-guided trans- abdominal puncture was the technique used to collect samples of amniotic fluid. In long-term cell cultures using Amniomax medium at 37 °C in a CO₂ incubator, amniotic fluid or any other foetal sample acquired was grown. After 6 days it was checked whether cell was sticked or not. If not sticked incubate for another 2 to 3 more days. After cell were sticked, they were arrested by Colchicine in methaphase. After chromosome harvesting, standard cytogenetics methods were applied to obtain spread chromosomes on the slide. G-Bands were induced by trypsin treatment and a resolution of the least 400 bands were obtained. Minimum 20 methaphase were analyzed for each case and karyotype were obtained.

RESULT: In our study 900 cases were examined, out of 45 prenatal cases had positive biochemical screening results, 33 had positive in Double marker and 12 Qquadruple marker results along with  ultra-solography. On the basis of Biochemical screening, all 45 high risk patients referred to the NIPT (Non-invasive) confirmation test.

TABLE 1: DISTRIBUTION OF PATIENT ON THE BASIS OF NIPT TEST RESULT

FIG. 1: DISTRIBUTION OF HIGH RISK PATIENTS ON THE BASIS OF RESULT OF KARYOTYPING +FISH TEST

TABLE 2: RESULT OF TRISOMY 21

Trisomy 21  (Down’s Syndrome) Karytotyping Result	Trisomy 21  (Down’s Syndrome) FISH Result

TABLE 3: RESULT OF TRISOMY 18

Trisomy 18 (Edwards’s Syndrome) Karytotyping Result	Trisomy 18 (Edwards’s Syndrome) FISH Result

FIG. 2:  RESULT OF ROBERTSONIAN TRANSLOCATION

TABLE 4: FREQUENCY OF CHROMOSOMAL ABNORMALITIES WITH RESPECT TO INDICATION

DISCUSSION: The most frequent genetic illnesses that cause birth malformations in newborns are chromosomal abnormalities. Chromosome abnormalities occur frequently (around 0.5% of live births, 5% to 13% of stillbirths, and 0.5% to 0.5% of neonates. Foetal abnormalities currently have no effective treatments. Second-trimester amniotic fluid cell karyotyping is a crucial preventive tool for prenatal detection and prompt cessation of abnormal pregnancies ⁴. After evaluating in our study, we found the incidence and type of chromosomal abnormalities in amniotic fluid samples using conventional cytogenetics analysis.  In our study, the invasive procedure was performed between 19 and 25 weeks of gestation Weeks. Similar, to other studies the most frequent indications for amniocentesis were positive maternal serum screening, abnormal ultrasound findings and advanced maternal age. We found numerical abnormalities in 2.33% and structural in 0.22% of cases. So far, the most frequent single abnormality was trisomy 21 (2 %), while other studies done by (Burada F et. al 2018) ¹ had  3%, (Gu X et al 2020) ⁵ had 4.4%) which is similar to present study while studied done by (Wang W et al 2020) ⁶ had 26%, (Pandey P  et al 2018) ⁷ had 93%, (Dai R et al 2019) ⁸ had 70.1%, (Li H et al 2019) ⁸ had 48.32%, and (Zhang S et al 2021) had 37.44% showed higher prevalence of Trisomy 21 because this study had a greater proportion of pregnant women and was a retrospective analysis with a longer duration frame. The reported incidence of prenatal chromosomal abnormalities is variable, while some studies indicated similar results with our finding. Another common frequent abnormalities was Trisomy 18 (0.33%), while other study done by (Gu X et al 2020) ⁵ had 1.33%, which is similar to present study while studied done by (Zhang S et al 2021) had 11.18%, (Li H et al 2019) ¹⁰ had 14.25%, (Dai R et al 2019) ⁸ has 16.2%, and (Wang W et al 2020) ⁶ had 24.5% showed higher prevalence of Trisomy 18 because this study had a greater proportion of pregnant women and was a retrospective analysis with a longer duration frame. Next abnormalities were Robertsonian translocation (0.22%). Similar observation was made by (Burada F et.al 2018) ¹ had 0.44%, (Gu X et al 2020) ⁵ had 0.08% and (Li H et al 2019) ¹⁰ had 2.6% showed almost similar result. In our study no of pregnant women is low or compared to most of the other studies. Cytogenetic analysis is an essential tool in genetic counselling to establish a definitive diagnosis, to estimate the risk of recurrence of the chromosomal disorders in future pregnancies, and to decide clinical management, which may account for the high prevalence of chromosomal abnormalities despite the availability of advanced prenatal diagnostic techniques in our country ¹¹.

TABLE 5: COMPARISON OF FREQUENCY OF CHROMOSOMAL ABNORMALITIES IN POPULATION OF THE PRESENT STUDY WITH OTHER STUDY

FIG. 3: COMPARISON OF STATE WISE FREQUENCY OF CHROMOSOMAL ABNORMALITIES IN THE PRESENT STUDY WITH OTHER STUDY

CONCLUSION: To avoid the delivery of foetuses with chromosomal disorders, karyotype screening of amniotic fluid is a crucial strategy. Our results underline the significance of cytogenetic investigations in individuals with signs of prenatal diagnosis because an aberrant finding not only gives patients the option of terminating or continuing their pregnancies but also serves as a foundation for genetic counselling and helps in creating a healthier society.

ACKNOWLEDGMENT: The authors would like to express sincere gratitude towards Usha Nursing Home and Sat Kaival Hospital, Anand in association with Gene Care Accuris Laboratory, Surat for providing the essential facilities to carry out this research.

CONFLICTS OF INTEREST: Nil

REFERENCES:

1. Burada F, Ioana M and Sosoi S: The Frequency of Chromosomal Abnormalities diagnosed prenatally in a Romanian population. WJPMR 2018; 4(1): 31-34.
2. Mesanovis S, Peric M and Vareskic: Prenatal screening of cytogenetic anomalies. A Ten Year Retrospective Study on 1510 Cases 2023; 5(3).
3. Pal AK, Amnulkar PS, Waghmare JE, Shende MR, Jain M and Shivkumar PV: Cytogenetics analysis for suspected chromosomal anomalies-Aretrospective study. Journal of Clinical and Diagnostic Research 2020; 14(5): 01-06.
4. Huafeng LI, Yongli LI, Rui ZHAO & Zhang Y: Cytogenetic analysis of amniotic fluid cells in 4206 cases of high-risk pregnant women. Iranian Journal of Public Health 2019; 48(1): 126.
5. Gu X, Liu S, Wang H, Weng R, Guo X & Zhong Z: Prenatal diagnosis of fetal chromosomal abnormalities among 2318 pregnant women with indications in southern China. A Retrospective Study 2020.
6. Wang WB, Wu Q, Zhou Y, Zhong X, Ge Y & Zhang J: A 10 year retrospective study on prenatal cytogenetic analyses. Clinical and Experimental Obstetrics & Gynecology 2020; 47(2): 248-252.
7. Pandey P, Verma RK, Kumar N & Koonwar S: Down syndrome: a cytogenetic study in North Indian population. Biomed Res 2018; 29: 3556-60.
8. Dai R, Yu Y, Xi Q, Hu X, Zhu H, Liu R & Wang R: Prenatal diagnosis of 4953 pregnant women with indications for genetic amniocentesis in Northeast China. Molecular CVytogenetics 2019; 12: 1-7.
9. Choudhari DR, Dalmia RD, Dahiwade SU and Garude SG: A comparison of detection of chromosomal abnormalities by Amniocentesis in patients screened by dual marker test vs those screened by ultrasonography for nuchal translucency and nasal bone in first trimester. Indian J Obstet Gynecol Res 2022; 9(3): 352-356.
10. Xie D, Yang W, Fang J, Li H, Xiong L, Kong F & Wang H: Chromosomal abnormality: prevalence, prenatal diagnosis and associated anomalies based on a provincial‐wide birth defects monitoring system. Journal of Obstetrics and Gynaecology Research 2021; 47(3): 865-872.
11. Santhi S, Sherrin T Alex, Aswathy CG, Babu George and Sankar VH: Structural chromosomal abnormalities in children with Intellectual disability and parental balanced chromosomal rearrangements: Importance of genetic counseling. Kerla Health Conference 2021; 12.
12. Cherian AG, Kamath V, Srivastava V, Danda S, Sebastian, T & Beck MM: Spectrum of Chromosomal Abnormalities Detected by Conventional Cytogenetic Analysis Following Invasive Prenatal Testing of Fetuses with Abnormal Ultrasound Scans. The Journal of Obstetrics and Gynecology of India 2022; 72(1): 209-216.
13. Kumar B, Singh M, Verma RK and Kumar N: Prevalence of chromosomal anomalies and correlation with indications of ultrasound and biochemical markers in highrisk pregnancies. Eur Chem Bull 2023; 12(4): 3739-3748.
14. Rai G, Singh S and Bhardwaj B: Invasive genetic testing in pregnancy: experience from a tertiary care center. International Journal of Reproduction, Contraception, Obstetrics and Gynecology 2021; 1; 10(5): 7.
    

    ---

    How to cite this article:

    Bhatiya A, Shah H and Vaishnav S: The prevalence of chromosomal abnormities diagnosed prenatally in a an and population. Int J Pharm Sci & Res 2024; 15(2): 501-05. doi: 10.13040/IJPSR.0975-8232.15(2). 501-05.

    ---

    All © 2024 are reserved by International Journal of Pharmaceutical Sciences and Research. This Journal licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.