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E Schwinger

Publications and source records attributed to E Schwinger.

At least 55 records · Page 3Linked to original sources
PubMed2000

Comparative study of disomy and diploidy rates in spermatozoa of fertile and infertile men: a donor-adapted protocol for multi-colour fluorescence in situ hybridization (FISH).

Spermatozoa from seven healthy donors (two of whom had already fathered children) and five infertile patients taking part in the local programme of intracytoplasmic sperm-injection (ICSI) were investigated for the disomy rates of chromosomes 13/21, 18, X and Y as well as for the diploidy rates. Two- and three-colour fluorescence in situ hybridization (FISH) was applied after a donor-adapted decondensation pre-treatment: in a preliminary decondensation series the optimum fluorescence signals were individually determined by variation of the concentration of the decondensation reagents and the duration of incubation with these reagents. Strict scoring criteria were applied. The average disomy rates ranged from 0.10% (chromosomes 13/21) to 0.44% (disomy XY) in the infertile donors and from 0.07% (disomy XX) to 0.36% (disomy XY) in the controls. The average diploidy rates were 0.22% and 0.20% for the infertile donors and the controls respectively. There was no statistically significant difference between the two groups with respect to the disomy and diploidy rates. Within the two groups there were inter-individual differences which were partly statistically significant, indicating considerable inter-donor variation of the aneuploidy rates.

Aneuploidy↗
PubMed2000

Prenatal diagnosis of single umbilical artery: determination of the absent side, associated anomalies, Doppler findings and perinatal outcome.

OBJECTIVE: To determine the absent side of a single umbilical artery and its association with malformations and abnormal karyotypes. METHODS: We prospectively studied 102 fetuses from 13 to 39 weeks of gestational age with a prenatally identified single umbilical artery. The absent side, pregnancy data, Doppler findings and the perinatal outcome were reviewed. RESULTS: (1) The left umbilical artery was absent in 71 (69.6%) and the right in 31 (30.4%) fetuses; (2) Single umbilical artery as an isolated finding occurred in 59 (57.8%) pregnancies and was not associated with aneuploidy. The mean gestational age at delivery in this group was 38.4 weeks and the mean birth weight was 3047 g. Six (10.2%) fetuses were small for gestational age, all of them with normal umbilical and uterine Doppler findings; and (3) Chromosomal abnormalities were diagnosed in 10 of 43 fetuses with single umbilical artery and congenital malformations. In nine of 10 fetuses with aneuploidy the left umbilical artery was not developed. Absence of the left artery occurred in 21 of 33 fetuses with sonographic anomalies and normal karyotype. Pathologic Doppler measurements of the umbilical artery were found in only one case of nonchromosomal abnormality. CONCLUSION: Our data suggest that in fetuses with single umbilical artery the absence of the left artery is more frequent than the absence of the right artery. The association with additional malformations seems to be equal on each side.

Abnormalities, Multiple↗
PubMed2000

Assignment of transcription factor NFAT5 to human chromosome 16q22.1, murine chromosome 8D and porcine chromosome 6p1.4 and comparison of the polyglutamine domains.

To date, transcription factors of the NFAT family (nuclear factors of activated T cells) have been described for mouse and man. Recently, we mapped the human NFAT5 gene to chromosome 16 by PCR using DNA from hybrid cell lines. Here we report the exact position of the human gene between D16S496 and WI5254 within the 16q22.1 subband, the localization of the murine gene at chromosome 8D, and the identification and mapping of the porcine counterpart to chromosome 6p1.4.

Animals↗
PubMed2000

Familial sarcoidosis is linked to the major histocompatibility complex region.

Sarcoidosis is a systemic granulomatous disorder associated with high CD4+ cell activity, but no pathogen is detectable. Clustering in families occurs, and the existence of a genetic predisposition to sarcoidosis is widely accepted. The major histocompatibility complex (MHC) is believed to contribute to this susceptibility. Many studies testing this hypothesis have produced conflicting results. We have genotyped 122 affected siblings from 55 families for seven DNA polymorphisms that flank and cover the MHC region on chromosome 6, and for HLA-DPB1, a candidate gene for granulomatous disorders. Multipoint nonparametric linkage (NPL) analysis showed linkage (NPL score > 2.5; p < 0.006) for the entire MHC region with a maximum NPL score of 3.2 (p = 0.0008) at marker locus D6S1666 in the Class III gene cluster. There was a significant excess of marker haplotype sharing among affected siblings. However, the frequency of HLA-DPB1 alleles on 104 shared chromosomes did not differ from that of a control group of founders from the family panel. Transmission disequilibrium was found for allele DPB1*0201, but only nine families contributed to this result. We conclude that genes of the MHC are involved in the genetic predisposition to sarcoidosis, but HLA-DPB1 alone does not sufficiently explain this fact.

Alleles↗
PubMed1999

Smooth pursuit performance in families with multiple occurrence of schizophrenia and nonpsychotic families.

BACKGROUND: Eye tracking dysfunction (ETD) has been put forward as a trait marker for biological susceptibility to schizophrenia with the hope of identifying a link to specific cerebral lesions. METHODS: Eye movements were recorded using infrared oculography in 8 families (67 members) showing multiple occurrence of schizophrenia and in 9 nonpsychotic families (80 members). Triangle wave stimuli at 15 degrees/s and 30 degrees/s were used and gains (eye velocity/target velocity), rates and amplitudes of different saccade categories (catch-up, back-up, anticipatory saccades, and squarewave-jerks) were determined. RESULTS: In the relatives, the same deficit in maintenance of smooth pursuit performance was found as was seen in the schizophrenic patients. This deficit, which was not observed in the nonpsychotic families, consisted of lower gains for leftward as compared to rightward pursuit. This was emphasized most clearly at 30 degrees/s and was associated with an excess of catch-up saccades in the schizophrenic patients, whereas in the relatives a tendency to exhibit more and larger anticipatory saccades was observed. CONCLUSIONS: The results confirm the hypothesis that eye-tracking dysfunction is a phenotypic marker for genetic liability to schizophrenia. Neurophysiologically, a cerebral dysfunction which includes one or more of the oculomotor centers can be assumed in subjects who carry a genetic susceptibility to schizophrenia.

Adult↗
PubMed1999

Tuberous sclerosis with intracardiac rhabdomyoma in a fetus with trisomy 21: case report and review of literature.

A large cardiac rhabdomyoma protruding into the left ventricle was diagnosed in a fetus at 21+2 weeks of gestation by grey-scale echocardiography. Obstruction to left ventricular outflow was ruled out by colour and spectral Doppler echocardiography. No other abnormalities were noted and karyotyping by cordocentesis revealed trisomy 21 (47,XY,+21). Post-mortem examination after termination of pregnancy confirmed the prenatal diagnosis of cardiac rhabdomyoma and in addition revealed fetal tuberous sclerosis. Demonstration of cardiac rhabdomyoma by prenatal ultrasound should raise suspicion of the presence of fetal tuberous sclerosis. Despite the incidental association with aneuploidy, fetal karyotyping is suggested for optimal counselling of parents.

Adult↗
PubMed1999

Genetic sonography as the preferred option of prenatal diagnosis in patients with pregnancies following intracytoplasmic sperm injection.

The option of prenatal diagnosis with nuchal translucency measurement at 10-14 weeks of gestation and second trimester targeted ultrasound including fetal echocardiography (genetic sonography) is reported in patients after intracytoplasmic sperm injection (ICSI). From January 1995 to December 1998, 153 consecutive patients, with a mean age of 32.3 years (+/-4.1) and 29. 6% >/= 35 years, who had become pregnant after ICSI, were studied. They attended our unit for first and second trimester sonography. Of these, 67.8% of primigravid and 80.9% of nulliparous women were included. Multiple pregnancy rate was 19.7%; 189 fetuses were screened in total. Due to the introduction of genetic sonography in 1995, the rate of invasive prenatal diagnosis decreased from 74% in 1995, to 48, 36 and 19% in 1996, 1997, and 1998 respectively. Two inherited numerical and structural chromosomal anomalies in clinically healthy children at birth (1.0%) and four major malformations in all liveborn children and late abortions (2.1%) were recorded. The results demonstrate that especially in women of advanced reproductive age with a long history of infertility, detailed genetic sonography may be a reasonable and highly accepted alternative to avoid even the relatively low risks associated with invasive screening procedures.

Adult↗
PubMed1999

Genetics of male subfertility: consequences for the clinical work-up.

Major principles of genetic failures, chromosomal alterations and the most common syndromes associated with male subfertility should be taken into account before medical therapy and sophisticated techniques of assisted fertilization are applied to help a couple conceive. This review addresses the most common genetic reasons for male subfertility or infertility with special regard to the importance for the clinical work-up in daily routine and the potential risks for the conceptus.

Chromosome Aberrations↗
PubMed1999

Isolation and characterization of novel CAG repeat containing genes expressed in human brain.

Neurodegenerative diseases may be caused by expansion of triplet repeats in human genes. To identify novel genes with CAG repeats, we screened a human brain cDNA library with an oligonucleotide probe. Four of the isolated cDNAs were sequenced, analyzed for polymorphisms, chromosomal localization, evolutionary conservation and expression. One of the repeats is bi-allelic with 10 triplets (80% of chromosomes) and 7 triplets (20% of chromosomes). In one of the genes two CAG repeats coding for 10 and 17 glutamines are localized in the same reading frame.

Animals↗
PubMed1999

hSKCa3: a candidate gene for schizophrenia?

Recently, case-control studies have suggested an association between the polymorphic CAG repeat in the neuronal potassium channel gene hSKCa3 and an increased susceptibility to schizophrenia, with larger repeats being overrepresented in schizophrenic patients. Therefore, we have examined the CAG repeat polymorphism in hSKCa3 and four adjacent microsatellite markers in 12 multiplex schizophrenia families. On performing the extended transmission/disequilibrium test (ETDT), neither allele-wise (P = 0.67) nor genotype-wise (P = 0.071) analysis yielded evidence to support linkage disequilibrium between schizophrenia and the hSKCa3 CAG repeat alleles. No significant results were produced performing parametric and non-parametric linkage analysis between schizophrenia and hSKCa3, as well as the four microsatellite markers. Thus, our study does not support the involvement of hSKCa3 in schizophrenia. Furthermore, we refined the physical localization on chromosome 1q21.3 using linkage analysis. No recombination was seen between markers D1S2624 and D1S1600 and the polymorphic CAG repeat in hSKCa3. LOD scores of 19.44 and 12.97, respectively, were obtained at a recombination fraction of 0.00.

Chromosome Mapping↗
PubMed1999

A point mutation (W70A) in the rod PDE-gamma gene desensitizing and delaying murine rod photoreceptors.

PURPOSE: To examine the corneal electroretinogram (ERG) of transgenic mice (W70A mice) carrying a point mutation (W70A) in the gene encoding for the gamma-subunit of rod cGMP phosphodiesterase (PDEgamma). METHODS: The ERG of W70A mice was compared with that of normal mice. Cone responses were separated from rod responses by light adaptation, whereas rod sensitivity was assessed by threshold stimulation with dim light. Spectral sensitivity curves of the ERG were obtained using a constant response criterion. RESULTS: The ERG of the W70A mouse has a desensitized, delayed rod b-wave at threshold, and a prolonged rod b-wave at higher flash intensities. The a-wave is absent even at maximal stimulation. The cone ERG of the W70A mouse is indistinguishable from that of normal mice. The spectral sensitivity of the W70A mouse is maximal in the UV spectrum, in contrast to the normal mouse, which is most sensitive in the green region of the spectrum. This supports the interpretation of the results as normal cone and abnormal rod function in the W70A mouse. CONCLUSIONS: The W70A mouse represents new model of stationary nyctalopia that can be recognized by its unusual ERG features.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1998

Mutation of the start codon in the FRDA1 gene: linkage analysis of three pedigrees with the ATG to ATT transversion points to a unique common ancestor.

Friedreich ataxia (FRDA) is a progressive neurodegenerative disorder caused by loss-of-function mutations in the gene encoding frataxin. Most patients with FRDA have trinucleotide repeat expansions in both alleles of the FRDA 1 gene. In patients heterozygous for the expansion the second allele may be inactivated by a point mutation. We identified the ATG-->ATT (M11) mutation of the start codon in three independent families. Individuals with symptoms of FRDA in these families are compound heterozygous for the repeat expansion and the ATG mutation. To look for a common founder of the M11 mutation, a detailed linkage analysis employing six polymorphic chromosome 9 markers was performed. We found complete haplotype identity for two of the three chromosomes with the point mutation. The third case shows partial conformity and may be the result of a single recombination event.

Adaptor Proteins, Signal Transducing↗
PubMed1998

HLA-DQB1 and HLA-DPB1 genotypes in familial sarcoidosis.

Numerous reports on the familial occurrence of sarcoidosis, on regionally different prevalences and on its associations with genetic polymorphisms point to the existence of predisposing genes. We have started to establish a collection of DNA from families with two or more sarcoidosis patients for the purpose of genetic linkage and association studies. In this report we present HLA class II genotypes of affected first-degree relatives from 17 families, including eight instances of affected parent and offspring, six sib pairs, and three sib triplets. Genotyping for HLA-DQB1 revealed an over-representation of DQB1*0603 and DQB1*0604 among alleles shared by affected first degree relatives. The same was found for HLA-DPB1*0201 (Glu69 positive). However, none of the sib triplets had any of these alleles in common.

Family↗
PubMed1998

Sonographically detected fetal and placental abnormalities associated with trisomy 16 confined to the placenta. A case report and review of the literature.

Trisomy 16 is the most frequent autosomal anomaly seen in early spontaneous abortions, accounting for 15 per cent of all chromosomally abnormal early spontaneous abortions. This trisomy is thought to be lethal in the non-mosaic state and incompatible with full fetal development. We report a case of placental trisomy 16 mosaicism detected after chorionic villus sampling (CVS). The patient was referred at 18 weeks of gestation on account of moderate intra-uterine growth restriction (IUGR). Detailed sonography showed a thickened and enlarged placenta with multiple 'cysts', polyhydramnios, a single umbilical artery and a small ventricular septal defect (VSD). CVS, amniocentesis (AC) and fetal blood sampling (FBS) were performed. After direct preparation of chorionic villi only 47,XX,+16 cells were seen. However, chromosomal analysis of cultivated amniotic fluid cells and fetal lymphocytes only showed a normal karyotype 46,XX. After direct preparation of a second CVS at 19 + 4 weeks of gestation the karyotype 47,XX+16 was confirmed in the contralateral part of the placenta and near the insertion of the umbilical cord. A normal female karyotype 46,XX was demonstrated by extensive karyotyping of various sites of the placenta, the neonatal skin fibroblasts and lymphocytes postnatally. In accordance with this observation the multiple 'cysts' of the placenta disappeared in the third trimester. We speculate that the sonographic findings of multiple round placental 'cysts' without a hyperreflective border may be caused by the trisomic cell lineages and therefore may be a sonographic marker of trisomy 16.

Abnormalities, Multiple↗
PubMed1997

CAG repeat analyses in frozen and formalin-fixed tissues following primer extension preamplification for evaluation of mitotic instability of expanded SCA1 alleles.

Neurodegenerative disorders, including spin-ocerebellar ataxias (SCA), Huntington disease (HD) and dentatorubral-pallidoluysian atrophy (DRPLA), are associated with unstable CAG repeats. To investigate the mitotic stability of the repetitive element in the genes for SCA1, SCA3, HD, and DRPLA we extracted DNA from up to 13 tissue samples from four deceased individuals with progressive neurological disorders and neuropathological signs. Due to the formalin fixation of some tissues the genomic DNA was highly degraded and unsuitable for amplification of fragments longer than 150 bp. After size selection and primer extension preamplification, specific analyses could be performed even for expanded alleles. In all four patients the SCA1 mutation could be demonstrated, in one case with remarkable somatic heterogeneity of the elongated allele, whereas alleles of the normal range were stable in all tissues examined.

Adult↗