Cytogenetic Studies in Indian Population suspected to have Klinefelter syndrome

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1 Journal of Advanced Research in Biology Volume 1, Issue 1&2-2018, Pg. No Peer Reviewed Journal Research Article Cytogenetic Studies in Indian Population suspected to have Klinefelter syndrome Shailesh Pande 1, Vidya Salaskar 2, Anurita Pais 3, Gauri Pradhan 4, Chaitali Parab 5, Yamini Jadhav 6, Smita Patil 7, Sunmeet Matkar 8 1 Head of Department, 3 Operations Head, 4 Section Head, 5 Deputy Section Head, 6 Senior Scientific Officer, 7 Scientific Officer, 2 Department of Cytogenetics, Metropolis Healthcare Ltd, Mumbai, India. 8 Senior Executive, Department of Medical Communications, Metropolis Healthcare Ltd, Mumbai, India. Abstract Klinfelter syndrome is a genetic condition in which there is a presence of an extra copy of sex chromosome X. It is the most common sex chromosomal abnormality seen in males. The objective of our study was to determine the frequency of Klinfelter syndrome and its various cytogenetic types in cases with clinical suspicion of Klinfelter syndrome received at the Department of Cytogenetics, Metropolis Healthcare Limited, Mumbai, India. The period of our study was 2 years from January-2015 to December This retrospective study was performed on peripheral blood (2-3 ml) freshly collected in sodium heparin green-top vacutainer tube obtained from 421 patients with clinical suspicion of Klinfelter syndrome. All the samples used in our study were received from all over the India and the test requested was Chromosomal karyotyping (KT). The 72- hour old cultures were set and analysed by GTG banding at band level. Out of 421 samples referred, about 83 (19.71%) showed chromosomal abnormality,68 (16.15%) cases showed extra copy of chromosome X. While, out of 421 cases17(4.03%) cases were detected with polymorphic variations. Knowing the cytogenetic status is very important for the genetic Counselor and clinician for the management. Keywords: FISH, Karyotype, Klinfelter Syndrome, Mosaic, Translocations Introduction Klinefelter Syndrome (KS) or 47, XXY is the most common sex chromosomal aneuploidy in humans. Almost 64% of the cases of Klinefelter Syndrome go undiagnosed. Prevalence of KS is around 1 in 780 to 1 in 1000 within the male population. About 40% of XXY/KS is due to maternal meiotic error. Fathers paternally originating KS may have marginally elevated levels of disomic XY sperm compared to maternally originating KS cases. This extra copy of X chromosome leads to involvement of multiple system and subsequent manifestations [1]. The manifestations have a wide range of expressivity ranging from the well below to well above Intelligent quotient (IQ), hypo-gonadism with hypo-genitalism and occasionally diabetes mellitus, mild to moderate ataxia, breast cancer, lung cancer, autoimmune disease. The classic form of KS, which is present in the % of the cases, is defined by a 47, XXY karyotype resulting from the aneuploidy of the sex chromosomes, whereas highergrade aneuploidies (e.g. 48,XXXY or 48,XXYY), structurally abnormal X chromosome (e.g. 47,iXq,Y) or mosaicisms (e.g. 47,XXY/46,XY) make up approximately in the remaining % of cases. The prevalence of KS (ranging from 0.1 to 0.2 % in newborn male infants) rises up to 3 4 % among infertile males and % in azoospermic patients [2], and it is the most frequent observed sex chromosomal anomaly, with an estimated frequency of 1:500 to 1:1000 men. KS has increased in the last years although in the absence of Corresponding Author: Dr. Shailesh Pande, Department of Cytogenetics, Metropolis Healthcare Ltd, Mumbai, India. Id: shailesh.pande@metropolisindia.com Orcid Id: How to cite this article: Pande S, Salaskar V, Pais A et al. Cytogenetic Studies in Indian Population suspected to have Klinefelter syndrome. J Adv Res Biology 2018; 1(1&2): Copyright (c) 2018 Journal of Advanced Research in BioScience and BioTechnology

2 J. Adv. Res. Biology. 2018; 1(1&2) 22 a concomitant rise in the prevalence of XXY aneuploidy. This may indicate that the rise of the KS might be related to the increasing of the paternal meiotic alterations. KS patients have a phenotype which is extremely variable, but without any obvious facial dysmorphology that make them indistinguishable from the boys with normal karyotype. [3] This study aimed to determine the frequency of KS and its various cytogenetic types in cases with clinical suspicion of KS received at the Department of Cytogenetics, Metropolis Healthcare Limited, Mumbai, India during the two years. Material and methods This retrospective study was conducted between January-2015 to December-2016 on 421 samples referred with history or clinical findings suggestive of Klinefelter Syndrome at Department of Cytogenetics, Metropolis Healthcare Ltd, Mumbai, India. Approximately 2 to 3 ml of peripheral blood was collected in Sodium heparin green top Vacutainers from the patients between the age group of 1 day to 38 years. Further, 72-hour cultures were set & analysed by GTG banding at band level. They were reported as per the guidelines of the International System for Human Cytogenetic Nomenclature (ISCN), College of American Pathologists (CAP) and National Accreditation Board for Testing and Calibration Laboratories (NABL). In our study, for every case around 20 to 30 chromosomes in metaphase were studied. While, around 50 to 100 chromosomes in metaphase were studied for the mosaic cases. Fluorescence in situ hybridization (FISH) testing was performed wherever applicable for low-grade mosaicism and for detecting the presence of SRY gene. Results In our study, within a period of 2 years, a total of 421 cases were studied for cytogenetic abnormality. All the cases were referred with clinical suspicion of Klinefilter Syndrome. Out of 421 cases, 83 (19.71%) cases showed chromosomal abnormality while 17 (4.03%) cases showed polymorphic variations. Out of 17 cases with polymorphic variations, inversion of chromosome Y was observed in 3 (17.64%) cases, inversion of chromosome 9 observed in 2 (11.76%) cases. Other polymorphic variations in the form of increase in the length of satellite on acrocentric chromosomes or increase in the length of heterochromatic region on long arm of chromosomes were seen in 12 (70.58%) cases. Polymorphic variations are considered as normal in this study. Of the 83 cases having chromosomal abnormality, 68 (81.92%) cases showed 47, XXY pattern. Out of 68 cases with abnormality, 5(7.5%) cases showed 46, XX pattern and FISH for SRY gene studies did not show presence of SRY on any of the chromosome. Two (2.40%) cases showed 46, XX pattern but FISH studies revealed presence of SRY gene on one of the chromosome X. Seven (8.43%) cases showed 48, XXXY pattern and one (1.47%) case showed translocation between chromosome 1 and chromosome 6. The results can also be interpreted from the karyograms observed in our study. Table 1.Frequency of chromosomal pattern in abnormal cases Type of chromosomal abnormality No. of cases 47,XXY 68(81.92%) 46,XX 5(7.5%) 46,XX but presence of SRY 2(2.40%) 48,XXXY 7(8.43%) Translocation between chromosome 1 and 6 (1.47%) Total 83 Table 2.Frequency of polymorphic variations seen Type of variation No of cases Inversion Y 3 (17.64%) Inversion 9 2 ( 11.76%) Increase in length of satellite (ps+) 8 (47.05%) Increase in length of heterochromatic region 4 (23.52%) Total 17

3 23 J. Adv. Res. Biology. 2018; 1(1&2) Figurs 46,X,inv(Y)(p11.2 q11.2) 14ps+ 46,XY,inv (9)(p11q13)

4 J. Adv. Res. Biology. 2018; 1(1&2) 24 46,XY,t(1;6)(p32;q13) 48,XXXY Discussion The patients with Klinefelter syndrome usually presents with wide range of intelligent quotient (IQ) [4]. They usually have long limbs, are relatively tall and slim in stature, having relatively small penis and testis in child-hood, while gynecomsatia and infertility is usually observed. 47,XXY Most of the cases with KS enter the puberty stage with normal characteristics [5]. A drop in the testosterone levels during the late-adolescence or early-adulthood has been reported in several studies [6,7,8]. It has also been reported that individuals with 47, XXY/XY mosaicism have better testicular functions and with XXYY may have mental and behavioural problem [9]. Early detection of the

5 25 cytogenetic status may help to improve the quality of life with appropriate medical intervention. Even though 47, XXY is the most commonly reported sex chromosomal abnormality, mosaic patterns (46, XY/47, XXY), additional X or Y, such as 48, XXYY, 48, XXXY, and 47, XYY are not uncommon abnormalities [10]. In our study, a total of 421 males with clinical suspicion of Klinefelter syndrome were studied. Cytogenetic abnormality was detected in 83 cases, while 17 cases showed polymorphic variations. Out of the 83 cases, 68 cases showed 47, XXY pattern, 5 cases showed 46, XX pattern while only 2 cases showed 46, XX pattern. In fact, FISH studies revealed the presence of SRY gene on one of the X chromosome. Around, 7 cases showed 48, XXXY pattern and one accidental finding of translocation between one of the chromosome 1 and chromosome 6. Inversion of Y was reported in 3 cases and inversion 9 in 2 cases but these are considered as normal polymorphic variations. Conclusion Klinefilter syndrome can have varied presentation and in case of clinical suspicion of KS, an early diagnosis during childhood is very important. If early detected, appropriate treatment can be started at appropriate time which can assist in achieving muscular built, increased bone mineral density, increase pubic and facial hairs, less irritability and increased strength and libido. Therefore, it helps to begin hormonal replacement therapy when started at the age of 11 to 12 years. Hence cytogenetic evaluation as a basic genetic test and genetic counselling can be very useful for the clinician for management of the case. Acknowledgement We the authors acknowledge the support provided by the management of Metropolis Healthcare Ltd, Mumbai. Conflicts of interest There is no conflict of interest whatsoever among the authors of this study. References J. Adv. Res. Biology. 2018; 1(1&2) 1. Forti G, Corona G, Vignozzi L, Krausz C, Maggi M. Klinefelter s syndrome: a clinical and therapeutical update. Sex Dev Gene Mol Biol Evol Endocrinol Embryol Pathol Sex Determ Differ 2010; 4(5): Groth KA, Skakkebaek A, Host C, Gravholt CH, Bojesen A. Clinical review: Klinefelter syndrome a clinical update. J Clin Endocrinol Metab 2013; 98(1): doi: /jc Samplaski MK, Lo KC, Grober ED, Millar A, Dimitromanolakis A, Jarvi KA. Phenotypic differences in mosaic Klinefelter patients as compared with nonmosaic Klinefelter patients. Fertil Steril 2014; 101(4): doi: /j.fertnstert Lee YS, Cheng AW, Ahmed SF, Shaw NJ, Hughes IA. Genital anomalies in Klinefelter s syndrome. Horm Res 2007; 68(3): Wikstrom AM, Dunkel L. Klinefelter syndrome. Best Pract Res Clin Endocrinol Metab 2011; 25(2): doi: /j.beem Host C, Skakkebaek A, Groth KA, Bojesen A. The role of hypogonadism in Klinefelter syndrome. Asian J Androl 2014; 16(2): doi: / X Robinson DO, Jacobs PA. The origin of the extra Y chromosome in males with a 47, XYY karyotype. Hum Mol Genet 1999; 8: Bojesen A, Juul S, Gravholt CH. Prenatal and postnatal prevalence of Klinefelter syndrome: a national registry study. J Clin Endocrinol Metab. 2003; 88(2): doi: /jc Morris JK, Alberman E, Scott C, Jacobs P. Is the prevalence of Klinefelter syndrome increasing? Eur J Hum Genet EJHG 2008; 16(2): doi: / sj.ejhg Lanfranco F, Kamischke A, Zitzmann M, Nieschlag E. Klinefelter s syndrome. Lancet 2004; 364(9430): doi: /S (04) Date of Submission: Date of Acceptance: