Análise citogenética em material de abortamento espontâneo / Cytogenetic analysis of material from spontaneous abortion

OBJETIVO: Descrever as anormalidades cromossômicas em material de abortamento espontâneo. MÉTODOS: Realizou-se compilação retrospectiva da análise de cariótipo em lâmina corada com Banda G por microscopia óptica e em material de 428 produtos de abortamento encaminhados para estudo. RESULTADOS: Foram observados 145 resultados normais (33,9 por cento) e 237 resultados anormais (55,4 por cento). Em 46 amostras não houve crescimento celular (10,7 por cento). As anormalidades numéricas foram as mais frequentes, destacando-se a trissomia do 16 (41 casos), a triplodia (27 casos), a monossomia do X (26 casos), a tetraploidia (13 casos) e a trissomia do 15 (13 casos). CONCLUSÃO: As alterações citogenéticas representam importante causa de perdas gestacionais e sua detecção auxilia o aconselhamento genético do casal. A trissomia do cromossomo 16 é a alteração mais frequentemente encontrada.

OBJECTIVE: To describe chromosomal abnormalities in spontaneous abortion material. METHODS: A retrospective compilation of karyotype analysis of slides stained with Band G was carried out by optical microscopy with materials of 428 abortion products referred for study. RESULTS: There were 145 normal results (33.9 percent) and 237 abnormal results (55.4 percent). In 46 samples there was no cell growth (10.7 percent). Numerical abnormalities were the most frequent, especially trisomy 16 (41 cases), triplodia (27 cases), monosomy X (26 cases), tetraploidy (13 cases) and trisomy 15 (13 cases). CONCLUSION: Cytogenetic alterations are an important cause of pregnancy loss and their detection helps the genetic counseling to the couple. Trisomy 16 is the most often found change.

A inclusão de novas técnicas de análise citogenética aperfeiçoou o diagnóstico cromossômico da síndrome de Turner / The inclusion of new techniques of chromosome analysis has improved the cytogenetic profile of Turner syndrome

OBJETIVO: Avaliar o efeito do aprimoramento da análise cromossômica sobre os achados citogenéticos de pacientes com síndrome de Turner (ST). MÉTODOS: Estudo retrospectivo dos resultados de cariótipo de 260 pacientes com ST, com análise das técnicas de bandamento, número de células avaliadas e pesquisa de sequências de cromossomo Y. Segundo o cariótipo, dividiu-se em 45,X; mosaicismo cromossômico sem Y; aberrações estruturais de cromossomos sexuais com ou sem mosaicismo; mosaicismo com cromossomo Y. RESULTADOS: O cariótipo 45,X foi o mais frequente (108), seguido de aberrações estruturais (88) e mosaicismo (58 sem Y e 6 com Y). A introdução de técnicas de bandamento e o aumento do número de células analisadas resultaram em redução progressiva de pacientes 45,X e aumento de aberrações estruturais. O estudo de sequências de cromossomo Y foi feito em 96 casos e foi positivo em 10. CONCLUSÕES: O aperfeiçoamento da análise cromossômica ao longo do tempo modificou o perfil citogenético da ST.

OBJECTIVE: To evaluate the effect of the improvement of chromosome analysis on the cytogenetic findings of Turner syndrome (TS) patients. METHODS: Retrospective study of the results of the karyotypes of 260 patients with TS, regarding banding techniques, number of cells analyzed and results of investigation of Y-chromosome sequences. According to karyotype, divided in 45,X; sex chromosome mosaicism without Y; structural aberrations of sex chromosomes with or without mosaicism; sex chromosome mosaicism with Y. RESULTS: 45,X was the most frequent karyotype (108), followed by structural aberrations (88) and mosaics (58 without Y and 6 with Y). Introduction of banding techniques and increase in the number of cells analyzed resulted in progressive decrease of 45,X karyotype and increase of structural aberrations. The study of Y-chromosome sequences was performed in 96 cases of which 10 resulted positive. CONCLUSIONS: Improvement of chromosome analysis over the years has modified the cytogenetic profile of TS.

Freqüência das anormalidades cromossômicas: importância para o diagnóstico citogenético / Frequency of chromosomal abnormalities: the significance for cytogenetic diagnosis

As anomalias cromossômicas fazem parte de uma das maiores categorias de doenças genéticas, sendoresponsáveis por diversas malformações congênitas e parte dos insucessos reprodutivos. Este estudo retrospectivo teve como principal objetivo analisar a freqüência de anomalias cromossômicas em 1171indivíduos, encaminhados para exame citogenético, no período de janeiro de 1998 a dezembro de 2007, aoAmbulatório e Laboratório de Genética da Unesp – Bauru. Os cariótipos foram previamente realizados com atécnica de bandeamento G em células obtidas a partir de cultura de linfócitos de sangue periférico. Os resultados mostraram 142 casos de cariótipos anormais, sendo as aneuploidias (45,1%) as mais freqüentes,seguidas pelas alterações estruturais (38,7%) e mosaicismos (16,2%). Concluiu-se que esses resultadosconcordam com a literatura pertinente, sendo de alta relevância o estudo citogenético tanto para diagnósticoem indivíduos malformados ou inférteis, como para esclarecer a etiologia da perda fetal e, assim, alertar à possibilidade de futuras malformações congênitas.

Chromosomal abnormalities are part of a larger category of genetic diseases, and responsible for various congenital malformations and part of the reproductive failures. The mainly objective of this retrospective work was to analyze the frequency of chromosomal abnormalities among 1,171 individuals referred to the Ambulatório e Laboratório de Genética, Unesp-Bauru for cytogenetic examination, from January, 1998 to December, 2007. The G-banding technique was previously used to prepare karyotypes of cells from lymphocyte culture of peripheral blood. The results showed 142 cases of abnormal karyotypes. The most frequent were aneuploidies (45.1%), followed by structural anomalies (38.7%), and mosaicisms (16.2%). It was concluded that these results are consistent with those in the literature, and they are important both for the cytogenetic diagnosis in malformed or infertile individuals, and also to clarify the etiology of fetal loss, and thus alert to the possibility of further congenital malformations.

A preliminary study on chromosome aneuploidy & mosaicism in early pre-implantation human embryo by fluorescence in situ hybridization.

BACKGROUND & OBJECTIVE: Chromosome aneuploidy plays an important role in infertility, early pregnancy wastage and perinatal mortality. Cytogenetic & fluorescent in situ hybridization (FISH) studies on developmentally arrested and morphologically poor embryo have shown high frequency of chromosomal abnormality and mosaicism. In this study, we attempted to evaluate chromosome aneuploidy and mosaicism on human embryos through the use of FISH. METHODS: Sixty one grade IV un-transferable embryos were obtained from 25 patients undergoing in vitro fertilization (IVF). Forty six embryos were studied by FISH; 15 were lost during transport and handling. FISH probes (non-commercial) for centromeres of chromosome X, Y, 1 and 18 were used for the study. Zona of embryos were dissolved in 0.01N HCl containing 0.1 per cent Tween 20 for 2-3 min. RESULTS: Interpretable FISH results were obtained in 24 embryos. Nineteen embryos (79.2%) were disomic (normal) for chromosome X/Y or 1/18 and five (20.8%) were abnormal. Among five abnormal embryos two were triploidy (from same patient), one was double mosaic aneuploidy, one was mosaic aneuploidy and one was trisomy for sex chromosome (XXY). There was eleven embryos with presence of Y chromosome i.e., male and three embryos were female. INTERPRETATION & CONCLUSION: Skewing of sex ratio (11M vs. 3F) and low chromosome aneuploidy were observed in this preliminary study, however, it will be premature to conclude as the numbers of embryos studied were limited and so were the numbers of FISH probes used.

Cytogenetic profile of Down syndrome in Alexandria, Egypt

During 1992-2001, 673 Down syndrome patients were referred to the Department of Human Genetics in Alexandria. Regular [free] trisomy 21 constituted 95.4% of cases; Robertsonian translocation 2.7%; and mosaicism 0.7%. In 8 cases, regular trisomy 21 was associated with structural or numerical chromosome anomalies. Translocation was parentally inherited for 33.3% of cases and maternal transmission was twice as common as paternal. Two translocated Down syndrome fetuses were diagnosed prenatally in at [14;21] carrier mother. Mean maternal age was high in regular trisomy 21 [38.2 years] but not in translocation [25.3 years]. There was an excess of males in all groups except the mosaic group where the male:female ratio was 0.67. Cytogenetic investigations assist in patient management and family counselling