MOLECULAR ANALYSIS OF RING Y CHROMOSOME IN A 10-YEAR-OLD BOY WITH MIXED GONADAL DYSGENESIS AND GROWTH HORMONE DEFICIENCY
Milenkovic T1,*, Guc-Scekic M2, Zdravkovic D1,3, Topic V4, Liehr T5, Joksic G6, Radivojevic D2, Lakic N2
*Corresponding Author: Tatjana Milenkovic, Department of Endocrinology, Institute for Mother and Child Healthcare of Serbia “Dr. Vukan Cupic,” Radoja Dakica 6-8, 11 070 Belgrade, Serbia; Tel.: +381-11-3018-109; Fax: +381-11-3108-257; E-mail: tanjamil@eunet.rs
page: 71

RESULTS

Karyotype analysis of G-banded lymphocyte chromosomes revealed a 45,X karyotype in 24/44 (54.5%) cells, a normal number of chromosomes with a small, dot-like ring chromosome in 17/44 (38.6%) cells, and 47 chromosomes with two ring chromosomes (Figure 1A and 1B) in 3/44 (6.8%) cells. We considered the small ring chromosome to have originated from the Y chromosome and described the patient’s karyotype as: mos 45,X[24]/46,X, r(?Y)[17]/47,X, r(?Y)x2[3]. Parental karyotypes were normal. The C-banding analysis of the heterochromatic Yqh region of the patient and his father showed the loss of this region in the patient and its presence in the father, suggesting a de novo origin of the ring chromosome. Fluorescent in situ hybridization using a Y chromosome centromeric α satellite probe demonstrated the absence of a fluorescent signal in 31/100 cells and the presence of one (19/100) and two (2/100) fluorescent signals in interphase nuclei and metaphase cells (Figure 1C and 1D). When a Y chromosome centromeric α satellite probe was used, one fluorescent signal was found on the ring Y chromosome, confirming its monocentric nature. The somatic karyotype was therefore described as: 45,X[31]/46,X.ishr(Y) (DYZ1+) [19]/ 47,X.ish r(Y) x2(DYZ1x2)[2]. SubcenM-FISH [25] characterized two ring (Y) variants in the patient’s karyotype: ish r(Y)(RP11- 115H13+, cepY+,RP11.71M14+) and ishr(Y;Y)(RP11- 115H13++, cepY++,RP11.71M14++) (Figure 2A). These were present in different combinations in at least three cellular subpopulations: 46,X,r(Y);47,X,r(Y)x2; 47,X,r(Y)+r(Y;Y). The additional ring (Y;Y) variant, found in only one cell, was a ring chromosome in the process of forming a double ring. Telo-FISH displayed an r(Y) chromosome with no telomeric signals (Figure 2C), thus confirming loss of telomeric regions on Yp and Yq. Fluorescent in situ hybridization with the subtelomeric probe Xp/Yp and probe for Yq12, demonstrated the presence of the Yp subtelomeres and deletion of Yq12 region on the r(Y). The double Y chromosome r(Y;Y) showed two signals for the Yp subtelomere region (Figure 2B). Polymerase chain reaction with primers for the heterochromatic region of the Y chromosome revealed that the whole of this Yq12 region was missing. Multiplex PCR with selected primers for AZF (the AZFa, AZFb and AZFc) region, SRY and ZFY/ZFX genes showed their presence (Figure 3). These results confirmed the presence of two breakpoints on the Y chromosome that led to formation of the ring: one on the Yp arm (between the subtelomeric region and the telomere) and the other on the Yq arm at Yq12.



Number 26
Number 26 VOL. 26(2), 2023 All in one
Number 26
VOL. 26(2), 2023
Number 26
VOL. 26, 2023 Supplement
Number 26
VOL. 26(1), 2023
Number 25
VOL. 25(2), 2022
Number 25
VOL. 25 (1), 2022
Number 24
VOL. 24(2), 2021
Number 24
VOL. 24(1), 2021
Number 23
VOL. 23(2), 2020
Number 22
VOL. 22(2), 2019
Number 22
VOL. 22(1), 2019
Number 22
VOL. 22, 2019 Supplement
Number 21
VOL. 21(2), 2018
Number 21
VOL. 21 (1), 2018
Number 21
VOL. 21, 2018 Supplement
Number 20
VOL. 20 (2), 2017
Number 20
VOL. 20 (1), 2017
Number 19
VOL. 19 (2), 2016
Number 19
VOL. 19 (1), 2016
Number 18
VOL. 18 (2), 2015
Number 18
VOL. 18 (1), 2015
Number 17
VOL. 17 (2), 2014
Number 17
VOL. 17 (1), 2014
Number 16
VOL. 16 (2), 2013
Number 16
VOL. 16 (1), 2013
Number 15
VOL. 15 (2), 2012
Number 15
VOL. 15, 2012 Supplement
Number 15
Vol. 15 (1), 2012
Number 14
14 - Vol. 14 (2), 2011
Number 14
The 9th Balkan Congress of Medical Genetics
Number 14
14 - Vol. 14 (1), 2011
Number 13
Vol. 13 (2), 2010
Number 13
Vol.13 (1), 2010
Number 12
Vol.12 (2), 2009
Number 12
Vol.12 (1), 2009
Number 11
Vol.11 (2),2008
Number 11
Vol.11 (1),2008
Number 10
Vol.10 (2), 2007
Number 10
10 (1),2007
Number 9
1&2, 2006
Number 9
3&4, 2006
Number 8
1&2, 2005
Number 8
3&4, 2004
Number 7
1&2, 2004
Number 6
3&4, 2003
Number 6
1&2, 2003
Number 5
3&4, 2002
Number 5
1&2, 2002
Number 4
Vol.3 (4), 2000
Number 4
Vol.2 (4), 1999
Number 4
Vol.1 (4), 1998
Number 4
3&4, 2001
Number 4
1&2, 2001
Number 3
Vol.3 (3), 2000
Number 3
Vol.2 (3), 1999
Number 3
Vol.1 (3), 1998
Number 2
Vol.3(2), 2000
Number 2
Vol.1 (2), 1998
Number 2
Vol.2 (2), 1999
Number 1
Vol.3 (1), 2000
Number 1
Vol.2 (1), 1999
Number 1
Vol.1 (1), 1998

 

 


 About the journal ::: Editorial ::: Subscription ::: Information for authors ::: Contact
 Copyright © Balkan Journal of Medical Genetics 2006