Not Para-, Not Peri-, but Centric Inversion of Chromosome 12

68262Med Genet 1998;35:682-684

Not para-, not peri-, but centric inversion of

chromosome 12 J Med Genet: first published as 10.1136/jmg.35.8.682 on 1 August 1998. Downloaded from

Asli N Silahtaroglu, Seniha Hacihanefioglu, Giulgiin S Giuven, Asim Cenani, Jutta Wirth, Niels Tommerup, Zeynep Tuimer

Abstract were biotin or digoxigenin labelled D12Z3 A 39 year old male with primary infertility (chromosome 12 centromere specific), biotin was diagnosed as having Klinefelter syn- labelled "All Human Centromere", and digoxi- drome by conventional cytogenetic analy- genin labelled "All Telomere" probes. In addi- sis, which also showed an abnormal tion, 100 ng digoxigenin labelled DOP-PCR chromosome 12. Fluorescence in situ product' of the YACs y922c8 (1390 kb), hybridisation (FISH) analysis ofthe aber- y968f7 (1580 kb), and y771h4 (1100 kb) map- rant chromosome using a 12 specific cen- ping to the subtelomeric region of the short tromeric probe showed a break in the arm of chromosome 12 were used. Labelling alphoid repeats followed by an inversion and hybridisation were carried out according to within the short arm, resulting in a pseu- Kievitis et al.6 dodicentric chromosome. Further FISH analyses using telomeric and subtelomeric probes showed that the other break- Results point was in the subtelomeric region ofthe Giemsa staining and GTL banding of the short arm. The karyotype is designated initial PHA stimulated lymphocyte chromo- 47,XXY,inv(12)(p1Opl3.3). To our knowl- somes of the patient suspected of having edge this is the first report of a case of Klinefelter syndrome showed 47 chromo- "centric inversion". somes, including an extra X chromosome and a (7 Med Genet 1998;35:682-684) chromosome 12 with an aberrant short arm, in all the cells analysed (fig 1). FISH analysis of The Genetic and Keywords: centric inversion; centromere fission; chromosome 12 using D12Z3 showed two sig- Teratology Research inv(l2); Klinefelter syndrome nals, one located at the original centromere and Centre (GETAM), the other in the telomeric region (fig 2). The Cerrahpasa Medical intensity of these two signals were similar to Faculty, Istanbul the discovery of the specificity of University, Istanbul, Following one another, though weaker than the centro- Turkey centromeric alpha satellite sequences for each meric signal on the normal chromosome 12. A N Silahtaroglu chromosome,' fluorescence in situ hybridisa- These findings indicated a centromeric fission http://jmg.bmj.com/ S Hacihanefioglu tion (FISH) using these sequences became an followed by inversion of the whole short arm of A Cenani important tool in resolving chromosome aber- chromosome 12. rations where conventional banding techniques Division of Biomedical Chromosomes were further analysed for the were FISH applications include Sciences, Cerrahpasa inadequate. primary constriction and to determine whether Medical Faculty, identifying the chromosome origin of marker the inversion involved the whole short arm or a Istanbul University, chromosomes and determining the localisation part of it. With CBG banding, the aberrant Istanbul, Turkey or involvement of the centromere and telomere chromosome was shown to contain two on October 3, 2021 by guest. Protected copyright. A N Silahtaroglu in inversions and translocations.2A Using heterochromatin regions, one located in the S Hacihanefioglu FISH, we have identified the breakpoints of a original centromeric region and the other in G S Guven inversion involving the short arm of A Cenani unique the telomeric region. The primary constriction chromosome 12 in a patient with Klinefelter was always at the telomeric site in 75 Department of syndrome. lymphocytes and 25 skin fibroblasts analysed. Medical Genetics, Simultaneous hybridisation with biotin la- IMBG, Panum Case report belled "All Centromere" and digoxigenin Institute, Copenhagen was referred University, A 39 year old male with infertility labelled "All Telomere" probes showed that the Blegdamsvej 3, 2200 to our centre suspected of having Klinefelter telomeric sequences were not inverted. Further Copenhagen N, syndrome. His testes were hypoplastic and he analysis ofthe telomeric region was carried out Denmark had azoospermia. The parents of the proband using the YAC probes y922c8, y968f7, and A N Silahtaroglu had died, but were non-consanguineous and y77 1h4, mapping to a region 2 cM, 5 cM, and N Tommerup phenotypically normal. There was no history of 15 cM from the telomere, respectively (fig 2). Z Turmer infertility in the family. The proband's two The FISH signals for y922c8 and y968f7 were Max Planck Institute brothers and two sisters, who had two or three stationary, while the signal for y771h4 had for Molecular children each, would not cooperate in the moved to the original centromeric region ofthe Genetics, Berlin, investigation. abnormal chromosome 12. This result indi- Germany cated that the distal breakpoint has occurred J Wirth Materials and methods between the YACs y968f7 and y771h4, 5-15 Correspondence to: Metaphase chromosomes prepared from PHA cM from the telomere. Dr Turmer. stimulated lymphocytes and cultured skin The karyotype of the patient is designated fibroblasts were analysed by standard Giemsa 47,XXY,inv(12)(pOp1 3.3) and the extended Received 5 December 1996 3.3:: Revised version accepted for staining and GTL and CBG banding. The karyotype is 47,XXY,inv(1 2) (pter->p1 publication 29 January 1998 commercial FISH probes (Oncor Inc) used plO->pl3.3::qlO-qter). Centric inversion ofchromosome 12 683

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Figure 2 Schematic representation of the short arm ofchromosome 12 and the FISH results. The breakpoints are represented by vertical arrows. The proximal breakpoint of the inversion is within the alpha repetitive centromeric region, as shown by the presence of two signals on the inverted chromosome 12 using D12Z3 as FISHprobe (C). The distal on October 3, 2021 by guest. Protected copyright. breakpoint of the inversion is localised to the subtelomeric region using YAC 968fp (A) and YAC 771h4 (B) as FISH probes. The hybridisation signal of YAC 968ff (A) remains in the telomeric region on the inverted chromosome 12, while the signal of YAC 771h4 has moved to the centromeric region (B), indicating that the breakpoint has occurred in a region 5-15 cM away from the telomere. Discussion function of the centromere." This is supported In a patient with Klinefelter syndrome we have by the detection ofpartial deletion of the alpha identified an inversion of the short arm of satellite sequences without any effect on chromosome 12, where one of the breakpoints mitotic stability or meiotic segregation'4 '5 and was within the centromeric alpha satellite studies suggest that as little as 140 kb of alpha sequences and the other in the subtelomeric satellite DNA may be sufficient for centromere region, 5-15 cM from the telomere (fig 2). function.'6 Furthermore, alpha satellite repeat Chromosome 12 is one of the chromosomes in sequences could be split into two without which inversions have been reported fre- functional loss of centromere activity." 17 18 In quently, including 14 pericentric and 19 para- the present case, although it is not possible to centric inversions.7"12 However, an inversion deduce the exact amount of the alphoid with a centromeric breakpoint has not been sequences, the intensity of the FISH signals reported previously, either for chromosome 12 was almost equal. Either of the centromeres or for any other human chromosome. We could thus be expected to have sufficient therefore suggest the term "centric inversion" alphoid sequences for normal centromere for this unique case. function. CBG banding results showed that the Since there is great individual variability in primary constriction was always in the telo- the number of alpha satellite repeats of a meric region, suggesting that only one of the specific centromere, the absolute amount of centromeres was active. However, FISH results alpha satellite DNA cannot be critical for the contradicted those of CBG banding, as in some 684 Silahtaroglu, Hacihanefioglu, Giiven, et al

metaphases the condensed fluorescent signal fied flow-sorted chromosomes. Genes Chrom Cancer 1992; 4:257-63. indicative of the primary constriction'9 20 was 6 Kievitis T, Dauwerse JG, Wiegant J, et al. Rapid subchromo- observed in the centromeric region. To define somal localization of cosmids by non-radioactive in situ the activity of the hybridization. Cytogenet Cell Genet 1990;53:134-6. J Med Genet: first published as 10.1136/jmg.35.8.682 on 1 August 1998. Downloaded from centromeres, studies with 7 Haagerup A, Hertz MJ. Pericentric inversion of chromo- antibodies specific to CENP-C and CENP-E some 12: a three family study. Hum Genet 1992;89:292-4. are required. 8 Speleman F, Van RN, De Vos E, Hilliker C, Suijkerbuijk RFS, Leroy JG. Molecular cytogenetic analysis of a familial Aneuploidy events, including Klinefelter pericentric inversion of chromosome 12. Clin Genet syndrome, have been reported in conjunction 1993;44: 156-63. 9 Pettenati MJ, Rao PN, Phelan MC, et al. Paracentric inver- with para- and pericentric inversions, implying sions in humans: a review of 446 paracentric inversions a possible interchromosomal effect increasing with presentation of 120 new cases. Am J Med Genet 1995; the risk of In 55:171-87. non-disjunction.9 12 one patient, 10 Kleckowska A, Fryns JP, Van den Berghe H. Pericentric Klinefelter syndrome and paracentric inversion inversions in man: personal experience and review of the of chromosome 12 occurred simultaneously, as literature. Hum Genet 1987;75:333-8. 11 Madan K. Paracentric inversions: a review. Hum Genet in the present case, though involving the long 1995;96:503-15. arm.'2 Various degrees of other infertility prob- 12 Singh RP. Klinefelter's syndrome with a 47,XXY,inv(12)(q15q24) karyotype. Clin Genet 1981;19: lems have also been reported in several male 188-90. inversion carriers, suggesting an effect of inver- 13 Willard H. Molecular cytogenetics of centromeres of human sions on 11 In chromosomes. Proceedings of the 10th International Chromo- infertility.9 the present case, some Conference, June 1989, Uppsala, Sweden: 47-60. though, the sterility is likely to be the result of 14 Wevrick R, Earnshaw WC, Howard-Peebles P, Willard HF. Klinefelter syndrome. Partial deletion of alpha satellite DNA associated with reduced amounts of the centromere protein CENP-B in a mitotically stable human chromosome rearrangement. Mol ANS is supported by the Turkish National Council of Scientific Cell Biol 1990;12:6374-80. and Technical Research (TUBITAK) through NATO research 15 Tumer Z, Berg A, Mikkelsen M. Analysis of a whole arm fellowships (1993). This work was supported by the Research translocation between chromosomes 18 and 20 using fluo- Fund of the Istanbul University (Project No O/III/3/130396) rescence in situ hybridization: detection of a break in the and the German Genome Programme/Deutsch Forschungsan- centromeric alpha-satellite sequences. Hum Genet 1995;95: stalt fur Luft- und Raumfahrt eV (grant no 4763), and the EU 299-302. Commission (BMH4-CT97-2268). 16 Brown KE, Barnett MA, Burgtorf C, Shaw P, Buckle VJ, Brown WR. Dissecting the centromere of the human Y 1 Willard HF. Chromosome-specific organisation of human chromosome with cloned telomeric DNA. Hum Mol Genet alpha satellite DNA. Am_Hum Genet 1985;37:524-32. 1994;3: 1227-37. 2 Silahtaroglu AN, Hacihanefioglu S, Yilmaz S, Tarkan Y, 17 Cantn ES, Khan TA, Pai GS. Fluorescence in situ hybridi- Cenani A, Tumer Z. A supernumarary marker chromo- zation (FISH) of a whole-arm translocation involving chro- some X identified by in situ hybridiation. Clin Genet 1995; mosomes 18 and 20 with a-satellite DNA probes: detection 47:270-3. of a centromeric DNA break? Am J Med Genet 1992;44: 3 Gordon LP, Dalton DJ, Martens RP, Tharapel TA, Wilroy 340-4. SR. Eludication of the centromere involvement in an inver- 18 Rivera H, Cantu JM. Centric fission consequences in man. sion (13) by fluorescent in situ hybridisation. J Med Genet Ann Genet 1986;29:223-5. 1993;30:414-16. 19 Therman E, Trunca C, Kuhn EM, Sarto GE. Dicentric 4 Tharapel AT, Qumsiyeh MB, Martens PR, et al. Identifica- chromosomes and the inactivation of the centromere. Hum tion of the origin of centromeres in whole arm transloca- Genet 1986;72:191-5. tions using fluorescent in situ hybridization with alpha sat- 20 Sullivan BA, Schwartz S. Identification of centromeric anti- ellite DNA probes. Am J Med Genet 1991;40:1 17-20. gens in dicentric robertsonian translocations: CENP-C and 5 Telenius H, Pelmear AH, Tunnacliffe A, et al. Cytogenetic CENP-E are necessary components of functional centro- analysis by chromosome painting using DOP-PCR ampli- meres. Hum Mol Genet 1995;4:2189-97. http://jmg.bmj.com/ on October 3, 2021 by guest. Protected copyright.