scholarly journals X/XY Chromosome Mosaicism: Turner Syndrome and Other Clinical Conditions

Author(s):  
Irena Andriuškevičiūtė ◽  
Loreta Šalomskienė ◽  
Lina Jurkėnienė ◽  
Algimantas Sinkus

X/XY Chromosome Mosaicism: Turner Syndrome and Other Clinical Conditions The 45,X/46,XY mosaicism shows a wide spectrum of phenotypes ranging from females with Turner syndrome, male or female pseudohermaphroditism, to appearently normal male development. Chromosome anomalies accompanying Turner syndrome were found in lymphocyte cultures of 236 patients. Chromosomal analysis revealed the karyotype 45,X in 118 (50.0%) patients. X monosomy mosaics or structural rearrangements of the X chromosome was established in 112 (47.5%) patients. The Y chromosome was found in six (2.5%) patients with typical features of Turner syndrome. In five mosaics 45,X/46,XY the proportion of the XY clone ranged from 46% to 76%. In one Turner syndrome patient only 47,XYY cells were found (solely blood culture investigated). In most cases of 45,X/46,XY mosaicism, the cause is considered to be the loss of the Y chromosome because of nondisjunction after normal disomic fertilisation. Five other patients with X/XY chromosome mosaicism showed mixed gonadal dysgenesis (two patients), one male pseudohermafroditism, one male with Pierre Robin syndrome, and one normal male phenotype. In two non Turner syndrome patients nondisjunction of the primary clone 46,XY was obvious and resulted in mosaicism 45,X/46,XY/47,XYY, the one patient contained dicentric Y. The similarities between X/XY Turner syndrome and other nosological entity of females possessing Y chromosome — the Swyer syndrome — are discussed.

1976 ◽  
Vol 34 (1) ◽  
Author(s):  
T. Maeda ◽  
M. Ohno ◽  
A. Ishibashi ◽  
M. Samejima ◽  
K. Sasaki

1989 ◽  
Vol 34 (2) ◽  
pp. 294-296 ◽  
Author(s):  
Harry Ostrer ◽  
C. Mark Clayton

2008 ◽  
Vol 48 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Torben Larsen ◽  
Claus Højbjerg Gravholt ◽  
Annette Tillebeck ◽  
Hanne Larsen ◽  
Marianne Bryder Jensen ◽  
...  

2004 ◽  
Vol 21 (6) ◽  
pp. 229-230 ◽  
Author(s):  
Kerstin Landin-Wilhelmsen ◽  
Inger Bryman ◽  
Charles Hanson ◽  
Lars Hanson

2000 ◽  
Vol 32 (1) ◽  
pp. 38-41
Author(s):  
Jin Woo Kim ◽  
Eun Hee Cho ◽  
Young Mi Kim ◽  
Jin Mee Kim ◽  
Jung Yeol Han ◽  
...  

2020 ◽  
Vol 8 (22) ◽  
pp. 5737-5743
Author(s):  
Xue-Fei Leng ◽  
Ke Lei ◽  
Yi Li ◽  
Fei Tian ◽  
Qin Yao ◽  
...  

2014 ◽  
Vol 26 (8) ◽  
pp. 1176 ◽  
Author(s):  
Adriana Valéria Sales Bispo ◽  
Pollyanna Burégio-Frota ◽  
Luana Oliveira dos Santos ◽  
Gabriela Ferraz Leal ◽  
Andrea Rezende Duarte ◽  
...  

Turner syndrome (TS) is a common genetic disorder in females associated with the absence of complete or parts of a second sex chromosome. In 5–12% of patients, mosaicism for a cell line with a normal or structurally abnormal Y chromosome is identified. The presence of Y-chromosome material is of medical importance because it results in an increased risk of developing gonadal tumours and virilisation. Molecular study and fluorescence in situ hybridisation approaches were used to study 74 Brazilian TS patients in order to determine the frequency of hidden Y-chromosome mosaicism, and to infer the potential risk of developing malignancies. Additionally, we describe one TS girl with a very uncommon karyotype 46,X,der(X)t(X;Y)(p22.3?2;q11.23) comprising a partial monosomy of Xp22.3?2 together with a partial monosomy of Yq11.23. The presence of cryptic Y-chromosome-specific sequences was detected in 2.7% of the cases. All patients with Y-chromosome-positive sequences showed normal female genitalia with no signs of virilisation. Indeed, the clinical data from Y-chromosome-positive patients was very similar to those with Y-negative results. Therefore, we recommend that the search for hidden Y-chromosome mosaicism should be carried out in all TS cases and not be limited to virilised patients or carriers of a specific karyotype.


Author(s):  
Yuri Morales López ◽  
Marianela Alpízar Vargas ◽  
Ana Lucía Alfaro Arce ◽  
Vicenç Font-Moll

The purpose of this presentation is to show elements associated to the study and analysis of pedagogical practices used by mathematics teachers, taking into consideration different approaches and conceptions derived from theories related to the role of the math teacher. The project highlights the need to use different strategies to analyze the processes occurring in the activities and tasks organized and implemented by the teacher. One of the main tasks in teacher training is to promote the capacity to noticing on the pedagogical activity, where noticing is understood as an inherent process to improve the quality of classroom management. In addition, different analysis models should be compared using examples and experiential practices and the different theories and research projects developed in this field related to this type of analysis. Knowing what happens in the classroom is a task inherent to the math teacher. For sure, if the teacher does not understand or is even able to perceive what is happening in the class, improvement actions are very difficult to implement. Consequently, math teachers must develop the capability of analyzing their pedagogical activity and the related elements. It is not about isolating variables and looking for causal relationships, but rather about understanding the teacher’s activity as the center of the multiple situations occurring in the classroom, which may be known more in depth, if the attention is focused on the organization, ordering, and execution of the tasks planned by the teacher. It must also be understood that the competence of analyzing mentioned here is not an isolated activity without an effect. Such analysis must be approached from an active perspective where scenarios are generated to mitigate complex situations or to value an approach different than the one happening in the classroom. Being aware that there are many aspects to analyze (most likely almost everything that happens is analyzable), we must take a stand on which situations are highly related to what happens in our classroom and which could eventually happen. With such a wide spectrum, some questions that need to be addressed are: What is important in the math education activity and who defines what is important? What elements are of interest to math teachers? How does the analysis conducted relate to the different models of the teacher's knowledge? How does our previous experience influence the assessments we make? How do we distinguish elements of interest to analysis? What is the relationship between reflecting and analyzing? At what stages of the teacher’s activity is an analysis required? What is the ultimate purpose of analyzing teaching activities? What competencies or skills are related to the analysis? What types of analysis are appropriate (content, cognitive, media, among others)? How can we balance the actions derived from the analyses we conduct? From all these questions the most important one that can guide the study of this reflection would be: What should be assessed in pedagogical activities and what is the objective of analyzing such pedagogical activities in math education?


2010 ◽  
pp. P1-304-P1-304
Author(s):  
B Bianco ◽  
MVN Lipay ◽  
KC Oliveira ◽  
AD Guedes ◽  
ITN Verreschi

Sign in / Sign up

Export Citation Format

Share Document