Molecular cytogenetic characterization of two small chromosome 8 derived supernumerary mosaic markers.

Two small supernumerary mosaic marker chromosomes (SMC) were identified by conventional cytogenetics, one prenatally, the other postnatally. Fluorescence in situ hybridization (FISH) techniques, including 24-color FISH, were applied to identify both SMCs and better characterize their constitution. Patient 1: a 29 year-old man, whose wife had a spontaneous abortion, was found to have a small ring of the pericentromeric region of chromosome 8 (47,XY,+r(8)(p11q11)/46,XY). Patient 2: a 37 year-old woman had amniocentesis. The fetus was found to have a SMC; its presence was confirmed postnatally. Several FISH techniques (24-color, whole chromosome paints, centromeres, telomeres, band 8p22) led to the identification of a small analphoid marker. The marker was an inversion-duplication for part of the short arm of chromosome 8 (47,XY,+inv dup (8)(p23pter)/46,XY). The 24-color FISH allowed us to conclude that both markers originated exclusively from chromosome 8. However, the structure and content of the markers were elucidated using other molecular cytogenetic techniques, showing their complementarity.

French multi-centric study of 2000 amniotic fluid interphase FISH analyses from high-risk pregnancies and review of the literature.

This prospective and multi-centric study confirms the accuracy and the limitations of interphase FISH and shows that any cytogenetics laboratory can perform this technique. With regard to the technical approach, we think that slides must be examined by two investigators, because the scoring may be subjective. The main problem with the AneuVysion kit concerns the alpha satellite probes, and especially the chromosome 18 probe, which is sometimes very difficult to interpret because of the high variability of the size of the spots, and this may lead to false negative and uninformative cases. The best solution would be to replace these probes by locus-specific probes. Concerning clinical management, we offer interphase FISH only in very high-risk pregnancies or/and at late gestational age because of the cost of the test. We think that an aberrant FISH result can be used for a clinical decision when it is associated with a corresponding abnormal ultrasound scan. In other cases, most of the time, we prefer to wait for the standard karyotype.

De novo highly complex chromosome rearrangement (CCR) involving five breakpoints with congenital anomalies analyzed by FISH.

We report on a child with ptosis, epicanthal folds, depressed nasal bridge, carp-shaped mouth, low set ears, hirsutism, pectus excavatum, and developmental and language delay presenting with a balanced complex chromosomal rearrangement (CCR). R- and G-banding methods and fluorescence in situ hybridization were used to document that this is a complex translocation with five breakpoints involving chromosomes 1, 7, 10 and 21.

Trisomy 17 mosaicism in amniotic fluid cells not found at birth in blood but present in skin fibroblasts.

This article describes a case of fetal trisomy 17 mosaicism found in amniotic fluid cells in one of two bichorial biamniotic twins without any sonographic anomaly. The extra chromosome 17 was absent from cord blood cells at birth but present on karyotype and in situ hybridization in cultured fibroblasts from skin biopsy. Clinical examination showed a few mild dysmorphic features and a moderate neurological involvement which may rather be related to prematurity. It therefore seemed important to obtain the karyotype on fibroblasts when a trisomic cell line was found in amniocentesis and not confirmed on blood lymphocytes, even in the absence of dysmorphic features. This should help to differentiate a real mosaic from a mosaic restricted to extra-fetal tissues.

Glucose metabolism during the final stage of human oocyte maturation: genetic expression of hexokinase, glucose phosphate isomerase and phosphofructokinase.

The low involvement of glucose metabolism in early preimplantation embryos has suggested the presence of metabolic blocks in the glycolytic pathway. Genetic expression of hexokinase (HK), glucose-6-phosphate isomerase (GPI) or phosphofructokinase (PFK) were qualitatively analysed using the reverse transcription nested polymerase chain reaction (RT-nested PCR) in individual human immature oocytes at the germinal vesicle (GV) stage and in single non-fertilised human metaphase II (MII) oocytes, after IVF or ICSI failures. Transcripts encoding for HK, GPI and PFK were detectable in the majority of the oocytes analysed, and with different expression patterns. GPI transcripts were consistently present and appear to be constitutively expressed during GV and MII stages. In contrast, low quantities of transcripts encoding for HK and PFK were observed in all oocytes analysed. Our data revealed that the metabolic block previously reported at GPI or PFK levels underwent post-transcriptional regulation. The expression profiles of HK and PFK transcripts in GV and MII reflect a low level of transcription or active translation of maternal transcripts during oocyte maturation. Nevertheless, enzymatic activities of HK and PFK have previously been determined in human oocytes. This suggests that HK and PFK may be accumulated in protein (enzyme) form instead of maternal mRNA during human oocyte maturation. The expression pathway of glycolytic metabolism reflects the presence of different mechanisms involved in gene expression/regulation at the transcriptional and translational level and their accumulation during human oocyte maturation.

[Association of celiac disease and esophageal small cell carcinoma]. / Association d'une maladie coeliaque et d'un carcinome de l'oesophage à petites cellules.

BACKGROUND: Coeliac disease is known to favor the development of neoplasia. Coeliac disease associated with small-cell carcinoma of the esophagus has not been reported to date. CASE REPORT: A 51-year-old man with coeliac disease known for several years was hospitalized for epigastric pain. Work-up led to the diagnosis of small-cell carcinoma of the lower esophagus. The patient was treated with 6 cycles of chemotherapy using an etoposide-ciplatinum protocol associated with 60 Gy radiotherapy starting at the third cycle. The patient has remained in complete remission 2 years after diagnosis. DISCUSSION: Small-cell carcinoma of the esophagus is an exceptional finding in a patient with coeliac disease. Chemotherapy associated with radiotherapy has been successful in our patient.

Assisted reproductive technology and complex chromosomal rearrangements: the limits of ICSI.

Complex chromosomal rearrangements are very rare events in the human population. According to our knowledge on the consequences of simple reciprocal translocations for male fertility, translocations involving three or more chromosomes are thought to lead to severe reproductive impairments in terms of meiotic disturbance or chromosomal imbalance of gametes. We report the case of a 48 year old man whose sperm count revealed either oligozoospermia (<10(3) spermatozoa/ml) or azoospermia. He was referred to the laboratory for in-vitro fertilization after intracytoplasmic sperm injection. Cytogenetic investigations showed a complex chromosomal rearrangement involving firstly a translocation between the short arm of chromosome 7 and the long arm of chromosome 13 and secondly a translocation between the short arm of the same chromosome 13 and the short arm of chromosome 9. Diagnosis was ascertained by fluorescence in-situ hybridization and staining of the nucleolar organizer regions. Theoretical study of the translocated chromosomes predicted a 'chain' configuration of the hexavalent at the pachytene stage of meiosis. In all, 32 modes of segregation were considered and only one resulted either in a normal or a balanced gamete karyotype. Genetic counselling and choice of appropriate artificial reproduction technique are discussed.

Fluorescent in-situ hybridization and sequence-tagged sites for delineation of an X:Y translocation in a patient with secondary amenorrhoea.

We describe a phenotypically normal female with secondary amenorrhoea due to a translocation of genetic material involving the long arm of chromosome X (Xq28) and the long arm of chromosome Y (Yq11). We used fluorescent in situ hybridization to localize the breakpoint on the Xq. The Y chromosome breakpoint was identified using polymerase chain reaction (PCR) detection of sequence-tagged sites (STS) specific for interval 5 at Yq11.21. The relationship between this X:Y translocation and premature ovarian failure is discussed.

Embryo selection by IVF, co-culture and transfer at the blastocyst stage in case of translocation.

The case report illustrates the successful association of in-vitro fertilization (IVF) and co-culture for the selection of the viable embryos in a female patient carrying a reciprocal balanced translocation.

Prenatal diagnosis of trisomy 9 mosaicism: two new cases.

We present two prenatal cases of trisomy 9 mosaicism, both of which presented intrauterine growth retardation (IUGR) and other abnormal ultrasound findings. In case A, mosaicism was found in amniotic fluid cell cultures, of which 65 per cent were trisomic cells, on average. In case B, trisomic cells were present in amniotic fluid cell cultures (12 per cent) but none were found in fetal cord blood. After autopsy, cytogenetic findings were confirmed in different tissue cultures. It is concluded that echographic indicators are a very useful tool for a correct prenatal diagnostic interpretation of trisomy 9. Suspected trisomy 9 mosaicism always requires further investigation and fetal cord blood cytogenetic analysis may not be considered as providing an accurate diagnosis of fetal trisomy 9.