Analysis for common chromosomal breakpoint regions among 586 carriers of reciprocal translocations from Henan Province / 中华医学遗传学杂志

Objective@#To determine the frequency, common chromosomal karyotypes and breakpoints, and involved regions among carriers of reciprocal translocations from Henan Province, and to explore the influence of common breakpoint regions on pregnancy and fetal development.@*Methods@#For 586 carriers of reciprocal translocations, the above features were retrospectively analyzed.@*Results@#The 586 reciprocal translocations were identified among 62 477 subjects, which yielded a frequency of 0.94%. Among these, 572 (0.92%) had abnormal fertility, and 14 (0.02%) had a history of abnormal fetal development. Statistical analysis showed that chromosomes 1, 4, 7 and 11 were most frequently involved, with t(11; 22)(q25; q13) being the most common type of translocation. In total 437 breakpoint regions were identified, with 11q23, 22q13 and 1p36 being most frequently involved, which resulted in infertility, abortion, embryo death, congenital malformation, development delay, mental retardation or a normal phenotype.@*Conclusion@#Above results indicated a 0.92% carrier rate for reciprocal chromosomal translocations in Henan. The location of breakpoint regions may affect the pregnancy and/or fetal development. Discovery of such regions may enable more accurate genetic, reproductive and developmental counseling for carriers, and provide reference for delineation of function and pathogenetic mechanism of the relevant genes.

Genetic counseling in carriers of reciprocal translocations involving two autosomes.

One of the main genetic causes involve in the pathogenesis of recurrent abortion is parental chromosomal abnormalities. The central concept in genetic counseling with such families is to estimate the probability of recurrence of unfavorable pregnancy outcomes. The main questions that consultants usually ask are: Why did this happen? What is the risk to be done again? Our cases were two families with repeated miscarriage. The pedigrees were drawn, the chromosomes of couples were studied, and estimation for recurrent risk was done. We tried to answer those two main questions and clear the results for them. Parental chromosome abnormalities were founded after karyotyping with GTG technique at 450 band resolution, revealing 46 chromosomes with balanced translocation of autosomes in one of the partner in both families. Recurrent risk was estimated as "high" for their future pregnancies in each family. Couples in which one partner is the carrier of such balanced translocation have increased risks of infertility, recurrent abortion, and delivery of chromosomally abnormal offspring. Genetic counseling of such couples, therefore, presents a unique challenge and should be considered in dealing with such families.

Cytogenetic Study for Reciprocal and Robertsonian Translocation / 대한주산의학회잡지

PURPOSE:This study was aimed to evaluate the incidence of translocation and types of translocations (reciprocal or Robertsonian) in cases of cytogenetic analysis. Method:The incidence of translocation was calculated and types of translocation were classified in 390 individuals who perfomed cytogenetic analysis in Hanyang University Hospital from January, 2005 to February, 2009. RESULTS:The overall incidence of translocation was 3.1% (12/390). Among these translocations, 8 cases were having reciprocal translocations showing karyotypes of 47,XXY,t(11;22)(q23;q11.2), 46,XY,t(4;8)(q31.1;q11.2), 46,X,inv(Y)(p11.3q11.23),t(8;9)(q24.3;q34.1), 46,XY,t(14;16)(q32;q22), 46,XX,t(6;7)(q27;p11.2), 46,XX,t(1;4)(q25;q33), 46,XX,t(3;5)(q25;q22) and 46,XX,t(1;2)(p36.1;p25.1) in each. Last 4 cases of translocations were Robertsonian translocations showing karyotypes of 45,XY,der (13; 15)(q10;q10), 45,XY,der(13;14)(q10;q10), 45,XY,der(13;14)(q10;q10)and 45,XX,der (22;22)(q10;q10) in each. CONCLUSION:Although patients are phenotypically normal, they might be balanced translocation carriers. In high risk patients, translocations are more frequent than normal population. Classification of translocation is necessary for further genetic counseling according to the types.

Chromosome 12;15 rearrangements in patients with recurrent miscarriage.

Background: An abnormal karyotype in either partner, especially featuring a translocation and/or inversion is considered to be a cause of recurrent miscarriages. It is generally assumed that recurrent miscarriage might be due to recurrent chromosomal abnormalities in the fetus due to a balanced aberration in one of the parents being inherited by the offspring in an unbalanced form. Aim: Evaluation of chromosomal rearrangements in couples with recurrent miscarriages. Materials and Methods: Peripheral blood was collected and lymphocyte cultures were set up. Slides prepared from the cell suspension were stained and screened for metaphases followed by karyotyping. Result: Balanced translocation was observed in the male partner in one case and in the female partners in the three other cases. Conclusion: Couples with recurrent miscarriage should be investigated for chromosomal rearrangements, thus helping in genetic counseling and providing the options for future pregnancies.

Retardo mental y cardiopatía en una portadora de una translocación balanceada / Mental retardation and cardiopathy in a carrier of a balanced translocation

Las translocaciones reciprocas balanceadas ocurren con una incidencia de 1 por cada 500 nacimientos. Un porcentaje de ellas es diagnosticado en adultos que consultan por problemas reproductivos, otras descubiertas de manera fortuita y muchas pasan desapercibidas porque los portadores no tienen sintomatología, ni problemas al concebir y tienen descendencia normal. Solo un 5%, cursa con anomalías fenotípicas, con o sin retardo mental, atribuible a una inactivación o pérdida de genes. Se reporta el caso de una niña de 3 años y 6 meses de edad, portadora de una translocación balanceada reciproca entre los cromosomas 2 y 11, que consulta al servicio de Genética por retardo del desarrollo sicomotor y convulsiones. Al examen físico la paciente presentaba: CC: 46,5cm. (­2DS), talla de 87 cm. percentil 3, clinodactilia de ambos quintos dedos, hipertricosis y un soplo sistólico debido a una insuficiencia tricúspides y una válvula aórtica bicúspide. La niña es el producto del tercer embarazo de un matrimonio joven, no consanguíneo, tiene dos hermanos varones, el mayor de 8 años, con la misma cardiopatía y en el otro hermano de 6 años se ausculta un soplo sistólico, de etiología a confirmar. El estudio cromosómico de la propósita, ambos padres y los dos hermanos, se llevó a cabo a través de las técnicas de cultivo de sangre periférica. Las láminas se analizaron con coloración convencional y Bandas G y C. Se examinaron treinta células por individuo. En la paciente se encontró una translocación reciproca balanceada, no así en los padres y hermanos, por lo cual se la considero de novo. Cariotipo: 46, XX,rcp (2;11)(p11;p11). Se reporta este caso por ser de interés ya que las características clínicas de la niña son atribuibles a la anomalía cromosómica pero no así la cardiopatía y también porque el número de portadores de translocaciones reciprocas balanceadas afectados es bajo.

The incidence of balanced reciprocal translocations is 1 for every 500 births. A percentage of them is diagnosed in adults consulting for reproductive problems, other are discovered fortuitously and many pass unnoticed because the carriers do not have either symptomatology or problems on conception and have normal descents. Only 5% of them deal with phenotypic anomalies, with or without mental retardation, attributable to an inactivation or loss of genes. Here we report the case of a 3­year­old girl and 6 months of age, carrier of a balanced reciprocal translocation between chromosomes 2 and 11, who consulted the service of Genetics for retardation of the psychomotor development and convulsion. To the physical examination the patient presented: CC: 46.5cm.(­2DS), size of 87 cm, percentile 3, clinodactyly of both fifth fingers, hypertrichosis and a systolic breath due to an tricuspid insufficiency and bicuspid aortic valves. The girl is the product of the third pregnancy of a young, non­consanguineous couple. She has and older brother who was 8 years old and presented the same cardiopathy and a 6­year­old brother with a systolic breath of unknown aetiology detected by auscultation. The chromosomal study of the patient, both parents and both brothers, was made by culture of peripheral blood. The slides were analyzed by conventional coloration and G and C bands. Thirty cells were examined per patient and a balanced reciprocal translocation balanced was found in the girl but not in the parents and brothers. Due to this, it was considered a de novo translocation. Karyotype: 46, XX, rcp (2; 11) (p11; p11). This case is reported for being of interest since the clinical characteristics of the girl are attributable to the chromosomal anomaly but not the cardiopathy and because the number of carriers of balanced reciprocal translocations affected is low.

Cytogenetic causes for recurrent spontaneous abortions - An experience of 742 couples (1484 cases).

BACKGROUND: First trimester pregnancy loss is a very common complication and a matter of concern for couples planning pregnancy. Balanced chromosomal rearrangements in either parent is an important cause of recurrent pregnancy loss particularly in the first trimester. AIMS: In this study an evaluation of the contribution of chromosomal anomalies in causing repeated spontaneous abortions was made. METHODS AND MATERIALS: A review of the cytogenetic data in 742 couples (1484 individuals) with recurrent spontaneous abortions who were examined for chromosomal aberrations in the period 1990-2003 is presented. Women who had at least two abortions, or spontaneous abortions preceded or followed by fetal deaths or birth of a malformed child, and patients who had recurrent spontaneous abortions (> 3) with normal live issue/s were studied. RESULTS: Chromosomal rearrangements were found in 31 individuals (2%). These abnormalities included 22 (2.9%) structural aberrations, 9 (1.2%) numerical anomalies. In addition to these abnormalities, 21 (3.2%) chromosomal variants were also found. CONCLUSION: Chromosomal analysis is an important etiological investigation in couples with repeated spontaneous abortions as it helps in genetic counseling and deciding about further reproductive options.

A Case of the Carrier of Reciprocal Translocation Which was Inherited from Patient with Recurrent Spontaneous Abortion / 대한산부인과학회잡지

A balanced translocation in a parent may produce unbalanced gametes leading to abortions or defective liveborn children, or interval infertility. It also may give rise to a balanced gamete resulting in a balanced carrier, or it may produce a cytogenetically normal gamete. The incidence of balanced chromosomal translocations in couples with multiple abortions was reported as 0% to 31%. This wide variation is related to the heterogeneous criteria used for patient selection. Because parents with balanced chromosomal rearrangements and history of only repeated abortions have a significant chance with each pregnancy of having a child with normal or balanced karyotype, the usual criteria for investigation include at least two abortions or reproductive losses. There is no evidence from several reported series that increasing the number of losses to three or more leads to any change in the yield of chromosomal rearrangements detected.

Clinical application of preimplantation genetic diagnosis (PGD) using fluorescence in-situ hybridization to balanced reciprocal or Robertsonian translocation carriers in human IVF-ET program / 대한산부인과학회잡지

OBJECTIVE: This study was performed to evaluate the efficiency of preimplantation genetic diagnosis (PGD) using fluorescence in-situ hybridization (FISH) in Robertsonian or balanced reciprocal translocation carriers in human IVF-ET programm. METHOD: FISH was carried out in 25 cycles of 15 couples. Two-color FISH analysis was performed on 54 polar bodies in 3 cycles and 234 blastomeres in 22 cycles. After FISH analysis, the embryos with normal FISH signals were transferred into mother's uterus. RESULTS: In FISH analysis of polar bodies, 18 nuclei of polar bodies were normal and 12 embryos were transferred in 3 cycles. FISH efficiency per oocyte was 95.0% in cases using polar bodies. In FISH analysis of blastomeres, 49 embryos were normal and transferred in 21 cycles. FISH efficiency per embryo was 92.7% using blastomeres. At present, three pregnancies were achieved. A girl and a boy were delivered. Both of them were translocation carriers. The other conceptus showed normal karyotype. CONCLUSIONS: According to this study, PGD using FISH can be successfully applied for the patients with translocations of chromosomes.

Confirmation Of Cytogenetic Diagnosis In Ph' Positive And Negative Cases By Fluorescence In Situ Hybridization.

Chronic myelogenous leukemia (CML) is a clonal bone marrow disease characteristics of CML is the presence of the Philadelphia (Ph1) chromosome which involves rearrangement of BCR-ABL genes as a result of reciprocal translocation between chromosomes 9 and 22. Cytogenetic analysis requires sufficient numbers of well-spread metaPhases, but, the recently described fluorescent in situ hybridization (FISH) technique can also be used on poorly spread metaPhases and on interPhase cells to identify the Ph1 chromosome. We have performed cytogenetic as well as FISH analyses using ber-abl probe to determine if 1) the two methods of analyses complement each other, and 2) FISH analysis is more sensitive in detecting the Ph1. Cytogenetic analysis on 23 patients with clinical diagnosis of CML, showed the presence of Ph1 chromosome in 15 patients, whereas 8 patients were Ph1 negative. Specimens from all the 23 patients were independently studied for the presence of Ph1 chromosome using FISH. A reliable correlation was seen between patients with Ph1 chromosome and hybrid signal in all the patients studied. In addition, 3 cytogenetically Ph1 negative patients showed significant numbers of cells with hybrid signal by FISH analysis. ber-abl hybrid was also seen in all the patients with Ph' + ve cells. These results underscore the significance of the FISH technique in identifying the ber/abl hybrids in cells from patients with normal karyotype and, therefore, has tremendous application in detecting minimal residual disease following chemotherapy or monitoring the persistence of leukemic cells after bone marrow transplantation.

A Case of Associated with Autosomal Reciprocal Translocation / 대한산부인과학회잡지

Infertility, defined as 1 year of unprotected coitus without conception, affects approximately 10 to 15% for couples of reproductive age. Approximately 35% of these cases are attributable to male factor infertility. A major cause of male infertility is chromosome abnormality, such as 47 chromosomes with an XXY karyotype. Early surveys of infertile males showed that the incidence of major chromosome abnormality in infertile males in azoospermic patients. When patients are treated for male infertility, a chromosome analysis including a search for abnormality at the DNA level, should be performed. We have experienced a case of autosomal reciprocal translocation in azoospermic patient. So we report this case with a brief review of literatures.