Biomedical subjects

S Munne

Publications and source records attributed to S Munne.

8 recordsLinked to original sources

PubMed2000

Is there an interchromosomal effect in reciprocal translocation carriers? Sperm FISH studies.

Chromosome translocations have been known to affect disjunction of chromosomes unrelated to the translocation in the mouse and in Drosophila. However, in humans, an interchromosomal effect in chromosome translocations has not been demonstrated. The availability of techniques that allow the study of nondisjunction in sperm cells has permitted us to evaluate the possibility of an interchromosomal effect in male translocation heterozygotes. In this study, multicolor fluorescence in situ hybridization was used to determine levels of disomy for the clinically relevant chromosomes X, Y, 13, 18, and 21 in 332,858 spermatozoa from nine reciprocal translocation heterozygotes and nine controls with normal karyotypes. The specific translocations studied were as follows: t(10;12)(p26.1;p13.3), t(2;18)(p21;q11.2), t(3;19)(p25;q12), t(5;8)(q33;q13), t(11;22)(q23;q11), t(3;4)(p25;p16), t(8;9) (q24.2;q32), t(10;18)(q24.1;p11.2), and t(4;10)(q33;p12.2). Comparisons of disomy rates between carriers and controls were performed by using the Mann-Whitney test. Our results showed that the rates of sex chromosome hyperhaploidy were similar in controls (0.21%) and in translocation carriers (0.19%). Similarly, the frequencies of disomy for chromosomes 13, 18, and 21 did not differ significantly between controls and carriers (0.05% versus 0.08%, 0.07% versus 0.03%, and 0.14% versus 0.20%, respectively). Sex chromosome nondisjunction was more common than nondisjunction of chromosomes 13 and 18 both in controls (P=0.0057) and in carriers (P=0.0008). Similarly, the rates of chromosome disomy for chromosome 21 were higher than those for chromosomes 13 and 18 in both controls (P=0.0031) and translocation carriers (P=0.0057). In our study, the excess of chromosome 21 disomy versus disomy of the other autosomes was more pronounced in carriers than in controls. Thus, although the difference of disomy 21 between controls and carriers was not statistically significant, it is worthy of attention.

Adult↗

PubMed2000

Current awareness

In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of prenatal diagnosis. Each bibliography is divided into 17 sections: 1 Books, Reviews & Symposia; 2 General Interest; 3 Normal Fetal Development; 4 Gametogenesis and Pre-implantation Diagnosis; 5 First Trimester Diagnosis; 6 Second Trimester Diagnosis; 7 Fetal Diagnosis by Ultrasound and Other Imaging; 8 Maternal Screening; 9 Screening for Carriers of Genetic Abnormality; 10 Technological Developments; 11 Confined Placental Mosaicism and Uniparental Disomy; 12 Molecular Cytogenetics; 13 Fetal Cells in Maternal Circulation; 14 Fetal Therapy; 15 Psychosocial Aspects; 16 Epidemiology and Environmental Factors; 17 Developmental Pathology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted

Journal Article↗

PubMed1999

Multicolor fluorescence in situ hybridization analysis of the spermatozoa of a male heterozygous for a reciprocal translocation t(11;22)(q23;q11).

A reciprocal translocation between chromosomes 11 and 22 is a site-specific translocation that has been seen in many families with no common ancestry. This translocation is of particular interest because balanced carriers have a 0.7-3.7% risk of having children with the supernumerary der(22), resulting from a 3:1 segregation. We have used a three color fluorescence in situ hybridization (FISH) with specific DNA probes to determine the chromosome segregation pattern of a male carrier of a translocation t(11;22)(q23;q11). The probes selected included a centromeric marker for chromosome 11, a marker closely linked to the centromere of chromosome 22, and a third probe distal to the translocation breakpoint of chromosome 22. The results showed that 3:1 segregation is preferential in this patient, with 40.1% of spermatozoa belonging to this segregation type. Alternate segregation followed with 27.4% of analyzed spermatozoa; 17.6% resulted from adjacent 1 and 12.5% resulted from adjacent 2 segregation. We detected 0.5% of presumably diploid spermatozoa. Complementary adjacent 1 products were observed at statistically different frequencies (P = 0.02). Complementary adjacent 2 products without recombination in the interstitial segments were also seen at different frequencies (P = 0.002). In 3:1 segregation, the products containing one chromosome were observed more frequently than those with three chromosomes (P = 0.0001). The 24,+der(22) gamete was seen more frequently than all of the other gametes combined which had 24 chromosomes resulting from 3:1 segregation. The results of this study demonstrate that in this t(11;22) carrier, 3:1 segregation is preferential but not exclusive.

Adult↗

PubMed1997

Treatment-related chromosome abnormalities in human embryos.

Mosaicism was studied in good quality embryos from four different centres in order to assess the effects of follicular induction and exposure to laboratory conditions on chromosomal status. The donated embryos were fully biopsied and analysed by fluorescence in-situ hybridization using probes for chromosomes X, Y, 13, 18 and 21, simultaneously. The number of abnormal cells present indicated the division at which mosaicism first occurred (4/4 cells at first division, 2/4 cells at second, 2/8 at third). The rate of mosaicism in embryos from different centres varied greatly (P < 0.001). Most of the mosaic embryos were obtained before 1991. In one clinic increased mosaicism was found in embryos obtained before 1991 when compared to embryos obtained thereafter. The results suggest that certain culture conditions and/or hormonal stimulation protocols may induce chromosomal abnormalities and partly explain differences in pregnancy rates between in-vitro fertilization centres.

Biopsy↗

PubMed1996

The presence of multinucleated blastomeres in human embryos is correlated with chromosomal abnormalities.

The purpose of the present study was to determine whether the presence of one or more multinucleated blastomeres during early embryonic development is associated with chromosomal abnormalities in sibling blastomeres of that embryo. Embryos with multinucleated cells (n = 47) detected on day 2 or 3 or development were compared to dividing embryos without multinucleation. Arrested embryos were excluded from this study. Chromosome abnormalities were detected using fluorescent in-situ hybridization (FISH) with X, Y, 18 and 13/21 chromosome-specific probes. Of 47 embryos included in this study, 76.6% were chromosomally abnormal, compared to 50.9% in the control group (P < 0.001). Excluding aneuploidy, which is originated in the gametes and not the embryo, the differences were even higher, with 74.5% of multinucleated embryos being chromosomally abnormal compared to 32.3% of non-multinucleated embryos (P < 0.001). Day of multinucleation appearance, number of nuclei per cell, number of multinucleated cells per embryo and developmental quality of the embryos as well as the type of fertilization (intracytoplasmic sperm injection versus standard insemination) were not found to affect the rate of chromosomal abnormalities in embryos with multinucleated cells. These results suggest that embryos with multinucleated cells may not be suitable for replacement and should be excluded unless no other embryos are available.

Blastomeres↗

PubMed1996

Update in preimplantation genetic diagnosis: successes, advances, and problems.

The field of preimplantation genetic diagnosis has undergone significant advances since the report of the first birth from this method in 1990. The first birth in the USA was reported in 1992, as was the first successful diagnosis and delivery of a baby free of a single gene defect disorder (cystic fibrosis and then Tay Sachs). Investigators have now reported approximately 40 births worldwide from preimplantation genetic diagnosis using the polymerase chain reaction and fluorescent in-situ hybridization methods to analyze single cells removed from early cleavage stage preimplantation embryos. The International Working Group on Preimplantation Genetics meets annually to discuss progress and pitfalls in this field. Although preimplantation genetic diagnosis offers hope to patients at risk of transmitting disease, there are many technical hazards of this experimental procedure. Technical difficulties must be overcome in order for preimplantation genetic diagnosis to become a standard clinical tool. This review will highlight some of the recent advances and problems in the field of preimplantation genetic diagnosis.

Age Factors↗

PubMed1991

Cytogenetic studies in human sperm.

Sperm chromosome studies were performed in seven males. One of them had a history of exposure to lysergic acid (LSD) although he was free of the drug for 1 year before the study began. Sixteen ejaculates provided a total of 555 fully analyzable sperm cells. The overall frequency of hyperhaploid sperm cells was 2% and that of structural abnormality 3.6%. The most common structural abnormality was chromosome breaks followed by small chromosome fragments of unknown origin. Three chromosome breakpoints, 10q25, 2q21, and 9q21, were involved twice in different chromosome or chromatid type aberrations. Two of these, 10q25 and 2q21, correspond to chromosomal locations known as common fragile sites.

Adult↗

PubMed1991

The effect of in-vitro ageing on mouse sperm chromosomes.

In-vitro ageing has long been suspected to affect adversely the ability of spermatozoa to fertilize and produce viable zygotes. A comparison of the first cleavage chromosome complement of 824 mouse embryos fertilized with fresh spermatozoa and 656 embryos fertilized with spermatozoa aged for 12, 24 or 48 h is reported herein. The chromosome analysis of first-cleavage embryos allows us to study directly the paternal and maternal chromosome complements which contribute to the embryo. Both chromosome clusters remain separate when an antimitotic agent is used to prevent metaphase synchronization, allowing identification of maternal and paternal chromosomes. We show that after sperm ageing, there is a decrease in the fertilization rate from 75% in the controls to 57.5% (12 h of ageing), 63.5% (24h of ageing) and 4.4% (48 h of ageing). Simultaneously, the level of chromosome structural abnormalities increase from 1.3% in the controls to 16.5% after 12 h of ageing, 18.8% after 24 h of ageing and 59% after 48 h of ageing. The incidence of aneuploidy and polyploidy is not affected by ageing of the spermatozoa. Most of the structural abnormalities are paternal in origin and are presumably induced by the ageing of spermatozoa.

Animals↗