Chromosomal abnormalities in couples with repeated fetal loss: An Indian retrospective study.

BACKGROUND: Recurrent pregnancy loss is a common occurrence and a matter of concern for couples planning the pregnancy. Chromosomal abnormalities, mainly balanced rearrangements, are common in couples with repeated miscarriages. PURPOSE: The purpose of this study is to evaluate the contribution of chromosomal anomalies causing repeated spontaneous miscarriages and provide detailed characterization of a few structurally altered chromosomes. MATERIALS AND METHODS: A retrospective cytogenetic study was carried out on 4859 individuals having a history of recurrent miscarriages. The cases were analyzed using G‑banding and fluorescence in situ hybridization wherever necessary. RESULTS: Chromosomal rearrangements were found in 170 individuals (3.5%). Translocations were seen in 72 (42.35%) cases. Of these, reciprocal translocations constituted 42 (24.70%) cases while Robertsonian translocations were detected in 30 (17.64%) cases. 7 (4.11%) cases were mosaic, 8 (4.70%) had small supernumerary marker chromosomes and 1 (0.6%) had an interstitial microdeletion. Nearly, 78 (1.61%) cases with heteromorphic variants were seen of which inversion of Y chromosome (57.70%) and chromosome 9 pericentromeric variants (32.05%) were predominantly involved. CONCLUSIONS: Chromosomal analysis is an important etiological investigation in couples with repeated miscarriages. Characterization of variants/marker chromosome enable calculation of a more precise recurrent risk in a subsequent pregnancy thereby facilitating genetic counseling and deciding further reproductive options.

Cytogenetic abnormalities in 222 infertile men with azoospermia and oligospermia in Iran: Report and review.

Background: Infertility affects approximately 10%-15% of couples in reproductive age. In half of the couples, causes are male-related, associated with impaired spermatogenesis. There is a complex correlation between genetics and infertility. Several factors affect on gametogenesis, from which factors that lead to chromosomal abnormalities are one of the best known. The aim of this study was to determine type and rate of chromosomal abnormalities in infertile azoospermic and oligospermic males in Iranian population. Materials and Methods: The records of a total of 222 participants were evaluated retrospectively. Results: As a whole we observed 13.96% chromosomal abnormality, from which 12.15% showed numerical and 1.8% showed structural abnormalities. Conclusion: Comparison of our results with the review of the literature shows a higher incidence (4- fold) of gonosomal, in particular, numerical gonosomal, chromosomal anomalies. Cytogenetic analysis is strongly suggested for infertile men, particularly in those who suffer from azoospermia.

Chromosomal abnormalities associated with mental retardation in female subjects.

Chromosomal abnormalities are thought to be the most common cause of mental retardation (MR). However, apart from a few selected types with typical aneuploidy, like Downs syndrome, Klinefelter syndrome, Turner syndrome, etc., the frequency of detectable chromosomal abnormalities in association with idiopathic MR is very low. In this study, we have investigated chromosomal abnormalities in female MR subjects (n = 150) by high-resolution GTG banding. Of them, 30 cases were diagnosed as Downs syndrome. Among the remaining (n = 120), chromosomal abnormalities/marked polymorphisms were detectable in only three MR cases (0.025).

Nuchal translucency: an ultrasound marker for fetal chromosomal abnormalities

CONTEXT: The literature shows an association between several ultrasound markers and chromosome abnormality. Among these, measurement of nuchal translucency has been indicated as a screening method for aneuploidy. The trisomy of chromosome 21 has been most evaluated. OBJECTIVE: To define the best fixed cutoff point for nuchal translucency, with the assistance of the ROC curve, and its accuracy in screening all fetal aneuploidy and trisomy 21 in a South American population. TYPE OF STUDY: Validation of a diagnostic test. SETTING: This study was carried out at the State University of Campinas, Campinas, Brazil. PARTICIPANTS: 230 patients examined by ultrasound at two tertiary-level private centers, at 10 to 14 weeks of gestation. DIAGNOSTIC TEST: The participants consisted of all those patients who had undergone ultrasound imaging at 10 to 14 weeks of gestation to measure nuchal translucency and who had had the fetal or neonatal karyotype identified. MAIN MEASUREMENTS: Maternal age, gestational age, nuchal translucency measurement, fetal or neonatal karyotype. RESULTS: Prevalence of chromosomal defects -- 10 percent; mean age -- 35.8 years; mean gestational age -- 12 weeks and 2 days; nuchal translucency (NT) thickness -- 2.18 mm. The best balance between sensitivity and specificity were values that were equal to or higher than 2.5 mm for overall chromosomal abnormalities as well as for the isolated trisomy 21. The sensitivity for overall chromosomal abnormalities and trisomy 21 were 69.5 percent and 75 percent, respectively, and the positive likelihood ratios were 5.5 and 5.0, respectively. CONCLUSION: The measurement of nuchal translucency was found to be fairly accurate as an ultrasound marker for fetal abnormalities and measurements equal to or higher than 2.5 mm were the best fixed cutoff points

Chromosomal abnormalities in leukemia in Iran: a pilot study

Objective-To carry out cytogenetics investigations on bone marrow and peripheral blood samples obtained from patients with leukemia. Methods-A total of 35 bone marrow or blood samples from all types of leukemia patients was referred to the Cytogenetic Laboratory of Tehran University of Medical Sciences. The referral centers were the Hematology and Oncology Centers in Shariati Hospital and the Children's Medical Center. Cell culturing including high resolution [HR] and Giemsa banding [G-bands by trypsin using Giemsa strain; GTG] were carried out according to standard protocols. Chromosome analysis was performed following international system for human cytogenetics nomenclature [ISCN] guidelines [1995]. Results-Among the 28 cases, chromosomal abnormality rate was 50% in acute myelogenous leukemia [AML], 80% in acute lymphocytic leukemia [ALL], 83% in chronic myelocytic leukemia [CML] and 100% in the Lymphoproliferative disease [LPD] groups. Two patients in the myeloproliferative disease [MPD]/CML group had normal karyotype and were therefore treated as MPD. The types of observed chromosomal abnormality were translocation 15/17 in AML-M3 patients, double trisomy 8 and 13 in an AML patient, hyperdiploidy of 50- 55 of chromosomes in a child with ALL, a double abnormality of Philadelphia and t 7/8 in a CML patient at blast stage and a complex variant Philadelphia translocation of a t4/9/22 in a CML patient. Conclusion-Despite being a pilot study with a small number of samples, the majority of patients demonstrated chromosomal abnormalities comparable to previously reported cases in other countries. The type of chromosomal abnormality was relevant to diagnosis and stage of the disease

Acerca das anormalidades cromossomicas / Chromosome abnormalities

As anormalidades cromossomicas constituem causas importantes de perda reprodutiva, malformacoes congenitas e retardo mental, alem de contribuirem de forma importante na morbi-mortalidade perinatal. Aproximadamente 15 porcento das gestacoes clinicamente reconhecidas na populacao terminam em aborto espontaneo e...

Mortalidad fetal tardía: Chile 1990-1996 / Fetal mortality rate: Chile 1990-1996

Se analiza la tasa de mortalidad fetal tardía (TMFT) en Chile entre los años 1990-1996. Hay un significativo descenso de ella y de los nacimientos. La TMFT del período fue de 5,2/1.000 nacidos vivos. Las TMFT fueron significativamente más altas en las madres mayores de 34 años (7,9/1.000), en el bajo peso al nacer (57,2/1.000) y en la prematurez (58,2/1.000). el 42,3 por ciento y el 44,7 por ciento de los mortinatos pesaban más de 2.500 g y eran mayores de 36 semanas, lo que se interpreta como un subdiagnóstico de retardo del crecimiento intrauterino. Las causas más importantes de mortalidad fetal tardía corresponden a patología placentaria y de los anexos ovulares, hipoxia intrauterina, patología materna pregestacional y malformaciones congénitas

Chromosome abnormalities in a maternity hospital in UAE: a 4.5 year retrospective study

To determine the pattern of chromosome abnormalities and the possible need for a cytogenetic service, a retrospective study was carried out from January 1993 to June 1997 on all requests for chromosome studies from the Al Corniche Maternity Hospital. There was a total of 1421 requests, of which 912 [64.1%] came from the Gynaecological Clinic, as part of the investigation of couples or patients with recurrent abortions, infertility or a bad obstetric history. A major abnormal karyotype was found in one of 36 partners with a female to male ratio of 3.2. From the Antenatal Clinic there were 186 requests for amniocentesis [including one chronic villous biopsy], of which 10 were abnormal [5.4%] and 395 requests for the Triple Test, 84 of which were abnormal, [66 for Down's syndrome and 17 for neural tube defect], but only 8 babies were found to be abnormal at birth. There were 323 requests from the Paediatric Department for studies on infants with congenital abnormalities or dysmorphic features. Of these 108 were abnormal out of which 81 [75%] were Down's syndrome, an incidence of 2.16/1000 live births. In all 3 study groups, a wide spectrum of abnormalities was seen including balanced and unbalanced Robertsonian and reciprocal translocations trisomies, sex chromosome abnormalities and mosaicisms, population variants and markers. Ninety [6.3%] cultures failed to grow, a possible consequence of the need to send specimens abroad for culture, emphasising the need for cytogenetic facilities locally within the U.A.E. The overall results were comparable to previously published studies elsewhere

The Korean collaborative study on 11,000 prenatal genetic amniocentesis

Since amniocentesis made prenatal diagnosis feasible in 1967, the method has been remarkably instrumental in obstetrical practice. A recent study conducted between 1980 and 1997 collected 11,000 amniocentesis procedures done at 10 university hospitals and tertiary centers in Korea. The study indicated that the use of amniocentesis on patients has increased steadily since 1980; however, the number has increased sharply for patients in the mid 1990's. In the 1980's, amniocentesis had been used primarily for patients in advanced maternal age groups (at least 35 years or older). In 1995, amniocentesis had been implemented for the detection of abnormal serum markers (37.6%), and by 1997, amniocentesis was involved in such diagnosis even more frequently (44.8%). Of the total number of uses, 270 (2.5%) involved the detection of chromosomal anomaly. In autosomal disorders, 96 Down syndrome, 33 Edward syndrome, and 6 Patau syndrome were diagnosed. In sex chromosomal anomaly, 10 Turner syndrome, and 10 Klinefelter syndrome were diagnosed. Added to that, 83 translocations, and 15 mosaicisms were diagnosed. Of the 322 cases with abnormal ultrasonographic findings, 21 (6.5%) resulted in chromosomal anomaly. The use of genetic amniocentesis as a prenatal diagnostic test for Korean women has risen 10-fold between 1988 and 1998. As stated earlier, amniocentesis had earlier been used primarily for those in advanced maternal age groups. Today, maternal serum markers and highly sensitive ultrasonic technology can detect many fetal anomalies which eventually necessitate amniocentesis.

Hernia diafragmática congénita y malformaciones asociadas / Congenital diaphragmatic hernia and associated malformations

La hernia diafragmática congénita (HDC) continúa siendo una patología que pone en peligro la vida a pesar de los adelantos en su manejo. Las malformaciones congénitas asociadas resultan ser uno de los factores más importantes que contribuyen a elevar las tasas de mortalidad en estos pacientes. En este trabajo presentamos nuestra experiencia con relación a esta anomalía, la cual forma parte del Estudio Colaborativo Latinoamericano de Malformaciones Congénitas (ECLAMC), enfocado principalmente en la asociación de la HDC con otras malformaciones congénitas, y revisamos los aspectos relacionados con el patrón de herencia involucrado en los casos familiares de HDC. En este estudio encontramos que las malformaciones mayores, especialmente las cardíacas y un bajo peso al nacer confieren un mal pronóstico a los recién nacidos con HDC

Arteria umbilical única y malformaciones asociadas: experiencia en el Hospital Clínico de la Universidad de Chile / Single umbilical artery and associated malformations: experience at Hospital Clínico, Universidad de Chile

La arteria umbilical única (AUU) es una malformación centinela que debe orientar a la búsqueda más exhaustiva de malformaciones asociadas que pueden no ser siempre evidentes, ya sea que estas se presenten en forma de síndromes o bien con un patrón desconocido. Este estudio incluye a los casos registrados de AUU en la Unidad de Neonatología del Hospital Clínico de la Universidad de Chile desde enero de 1978 hasta abril de 1998. Observamos, como se ha reportado en la literatura, que la AUU aislada o asociada a malformaciones menores tiene buen pronóstico en contraposición a lo que ocurre cuando se acompaña de una o más malformaciones mayores. Se encontró a la AUU como parte de un síndrome en un 36,4 por ciento de los casos y se detectaron causas cromosómicas en 10,9 por ciento de ellos. Es importante intentar realizar un diagnóstico preciso, de manera de estimar el riesgo de recurrencia que puedan tener los padres en futuros embarazos

Trisomy 18 in Kuwait: a study of two decades

One hundred and eighteen patients with regular Trisomy 18 [T18] were ascertained clinically and cytogenetically in the Kuwait Medical Genetics Centre. The aim of this study was to provide an overview of T18 cases in Kuwait and highlight some associated factors, [out of the ascertained 118 T18 cases, 59 were delivered during the period 1994-1997]. The overall incidence rate during the years 1994 to 1997 was 9/10,000 livebirths [95% confidence interval 6.7 to 11.2 per 10,000 livebirths], which is considered high. The male:female ratio among T18 cases was 1:2.1. To investigate the factors associated with T18, a group-matched case-control study was undertaken which included 131 normal healthy controls. The mean maternal age of the T18 patients' mothers [31.9 years] was significantly higher [p=0.002] than the controls' mean maternal age [27.1 years]. Abnormal presentation was recorded in 14.4% in T18 cases compared to 5.4% in controls, while the mode of delivery was abnormal in 43.2% of cases [90% of them were cesarean section] compared to 15.3% in controls, [p<0.001]. Polyhydramnios occurred in 9.3% of the T18 cases versus 1.5% in controls, [p<0.001]. Significant seasonal variation in T18 cases was detected with a peak in spring [March-May], [p<0.05]. The most common anomalies observed were congenital heart [38.1%], gastrointestinal malformations [25.4%], limb anomalies [24.6%], microcephaly [20.3%], omphalocele [11%], eye anomalies 11% and genital anomalies [9.3%]. Multiplicity of malformations was noticed: [24.6% had only one malformation, 24.6% had two malformations, 17.8% had 3 malformations and 9.3% had 4 malformations]. In conclusion, the T18 incidence rate in Kuwait is high with possible associated factors of advanced parental age, polyhydramnios, abnormal presentation and mode of delivery

Situación de los servicios de genética en Chile / Status of genetic services in Chile

Due to the demographic changes in Chile, where preventable causes of death are being controlled and congenital malformations arise as an important cause of morbidity and mortality during infancy, of pathological pregnancies and reproductive alterationns, medical genetics is becoming increasingly importtant. Using data from an inquiry that was answered by thirteen medical genetic centers in the country, this article reviews the history of the discipline in Chile, the available resources, the existent services, the main problems found and their eventual solutions genetics teaching and the research that is being conducted

Aborto espontáneo: estudio citogenético en 609 casos / Spontaneous abortion: cytogenetical study in 609 cases

Cromosomal abnormalities are the most frequent cause of first trimester spontaneous abortions (SA). During the period Sep. 1989 through May 1996 we have cytogenetically studied 640 embrionic tissue samples obtained from cases of SA. Of these, 609 samples (95,1 percent) were successfully karyotyped. An abnormal karyotype was observed in 388 cytogenetically normal and abnormal embryos. The most frequent abnormalities detected were autosomal trisomies (239/388 [61.6 percent]) followed by triploidy (62 cases, 16 percent), monosomies (41 cases, 10.6 percent) and teraploidy (17 cases, 4.4 percent). The single most common anomaly observed was trisomy 16 (73 cases, 18.8 percent). The frequency of trisomies, with the exception trisomy 16, was related with advanced maternal age