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Biomedical subjects

E Schwinger

Publications and source records attributed to E Schwinger.

At least 145 records · Page 8Linked to original sources
PubMed1986

Dermatoglyphic peculiarities in families with X-linked mental retardation and fragile site Xq27: a collaborative study.

The dermatoglyphic patterns of fingertips, palms and soles of 75 male patients with X-linked mental retardation and fra-Xq27 and of 28 obligate female heterozygotes were analyzed and compared with the data from 200 male and 200 female control individuals. The results show that there is a strong association between the fra-X-syndrome and dermatoglyphic peculiarities observed in male patients and also in female heterozygotes. The characteristic dermatoglyphic features of the fra-X-syndrome are: increased frequencies of radial loops, whorls and arches on the fingertips, a pronounced transversal course of palmar ridges, lower a-b RC, absence of c-triradii on the palms, abnormal palmar and plantar creases, dysplasia of the papillary ridges and low frequencies of true patterns on the soles. Some of these patterns were found in the female carriers of fra-Xq27 also. The combination of palmar and plantar patterns, expressed by a "log. score-Index", provides a high degree of discrimination between the male patients with fra-X-syndrome and the control group. A preliminary log. score-Index was developed also for the female heterozygotes. A "phantom picture" of the dermatoglyphic stigmata is constructed. We suggest that dermatoglyphic examination of the members of families suspected for fra-Xq27-syndrome can be useful for predicting this state and for diagnosing male hemizygotes and carrier females.

Adolescent↗
PubMed1986

A family with Huntington disease and reciprocal translocation 4;5.

We report the clinical and cytogenetic findings in a family in which a balanced reciprocal translocation between the long arm of chromosome 4 and the short arm of chromosome 5 is segregating together with Huntington disease in 2 generations. In situ hybridization studies revealed that the linked human DNA marker is located on the short arm of the normal and translocated chromosome 4 in the region 4p16. The association between Huntington disease and the translocation in this family may represent a chance occurrence. However, it is also possible that there is an undetected rearrangement of DNA on chromosome 4 involving the gene for Huntington disease but not affecting the site of the linked marker. Finally, the likelihood that this represents heterogeneity cannot be excluded.

Adult↗
PubMed1985

On the significance of true trisomy 20 mosaicism in amniotic fluid culture.

Nine new cases of prenatally detected true mosaic trisomy 20 (T20) are reported. In three instances the fetuses were aborted. One fetus showed multiple malformations associated with a high percentage of T20 cells among amniotic fluid (AF) cells and fibroblasts of different fetal tissues. In two other fetuses only a slight facial dysmorphy was seen which was accompanied by a low percentage of T20 cells among AF cells. In five instances the pregnancies were carried to term, and normal somatic and psychomotor development of the children has been observed, in one case up to the age of 24 months. In one case the pregnancy is continuing. The T20 cells were not detected among cultured lymphocytes of these children. A review of the hitherto known cases of prenatally detected mosaic T20 indicates a relationship between the prenatal findings and the fetal development. This may serve as a provisory basis for genetic counselling: in the case of a percentage above 50% of T20 cells among AF cells there seems to be a risk of about 50% for the fetus to be affected by severe anomalies. However, in cases of a prenatally detected mosaic T20 with a percentage equal to or less than 50, fetal or congenital malformations have not been observed among 23 individuals so far examined.

Adult↗
PubMed1985

Recurrent mutation pressure does not explain the prevalence of the marker (X) syndrome.

In order to test the hypothesis that the high prevalence of the mar(X) syndrome is caused by a high mutation rate in male germ cells only, the fraction of new mutants among mothers of probands in 112 informative families has been examined by segregation analysis among their brothers and sisters. The estimated fraction of new mutants among these mothers is much lower than expected if a stable equilibrium existed between an unusually high mutation rate and a selective disadvantage of mentally retarded, male and female mar(X) carriers. Hence, the above-mentioned hypothesis could not be confirmed.

Female↗
PubMed1985

[Sporadic and familial-occurring multiple sclerosis. HLA typing and study of chromosomal sister chromatid exchange rate].

HLA and sister chromatid exchange (SCE) has been investigated in 17 multiple sclerosis cases and 10 controls. While the HLA showed no differences between familial cases of MS and the control group, in sporadic cases of MS the occurrence of the antigen A3 and B7 have been confirmed. The study showed a significant increase of the SCE-rate in sporadic cases of multiple sclerosis, in the contrary, in those cases with familial occurrence no changes in the SCE-rate could be found. A different etiology for sporadic and familial cases of multiple sclerosis is assumed.

Gene Frequency↗
PubMed1985

[Gynecologic and cytogenetic aspects of prenatal diagnosis in the 1st trimester of pregnancy].

The article reports on a new method in prenatal diagnosis during the first three months of pregnancy. The gynaecological as well as the cytogenetic aspects are discussed on the basis of 74 transcervical trophoblast aspirations. Two different experimental preliminary examination series were conducted. In the first study, the failure rate in respect of recovery of material was 12.5%, whereas in the second examination series all aspirations were successful. Thanks to these favourable results, transcervical trophoblast aspiration was adopted as the only method used in prenatal diagnosis. In cytogenetic processing, direct chromosome preparation was found to be rather costly and time-consuming, whereas the short-term culture of chorionic villi usually yielded more favourable results in respect of mitotic rate and quality of the metaphase plates. It must be considered a drawback of transcervical trophoblast aspiration that it is not possible to conduct alpha-foetoprotein determination or determination of acetylcholine esterase as part of prenatal neural tube diagnosis. However, this can be subsequently done-with suitable disposition--during the 16th week of pregnancy, or can be replaced by a determination of alpha-foetoprotein in the serum of pregnant women.

Abortion, Induced↗
PubMed1985

[Dysplasia of the corneal limbus, the mesodermal iris layer and the jaw skeleton in a family].

Ten members of the family B./A. (belonging to two generations) who had dysplasia of the anterior mesodermal layer of the iris were examined. Several of them also had moderate microcornea. The shape of the skull was remarkable, with micrognathia, in some cases combined with mandibular prognathism and early loss of the teeth. Members of the older generation suffered from pannus, although only pingueculae had been present in youth and adolescence. The anomaly of the anterior part of the eye combined with "dysostosis maxillofacialis" (Peters and Hövels) may represent an abortive form of Rieger's syndrome. An aggressive pannus does not appear to have been described before in this syndrome or related diseases.

Adult↗
PubMed1984

Heterozygous female carriers of the marker-X-chromosome: IQ estimation and replication status of fra(X)(q).

The IQ levels of 18 female carriers with the marker X chromosome were evaluated, and cytogenetic studies after BrdU incorporation were performed. A highly significant correlation between mental capacity and replication pattern of the X chromosomes could be demonstrated. Heterozygous females with normal intelligence showed a clear tendency to carry the fragile site at the late replicating X chromosome, while other female carriers with lower intelligence or mental impairment expressed their fragile site mainly with the early replicating X chromosome. This observation could be interpreted as an expression of Lyonisation .

Adolescent↗
PubMed1984

Transmission of the marker X syndrome trait by unaffected males: conclusions from studies of large families.

It is well established that apparently unaffected males can be transmitters of the marker X syndrome trait. Cytogenetic and clinical investigations of these male transmitters are only rarely reported for most of these male transmitters are dead by the time the syndrome is diagnosed in their families. We report on cytogenetic and clinical investigations of two unaffected male carriers of the disorder from two large families. Pedigree analysis of these families revealed six other cases of possible male transmission of the marker X syndrome trait. Mental impairment was not reported from the siblings of these unaffected male carriers and could not be observed in their daughters. The mode of transmission of the disorder cannot be fully explained by X-linked inheritance. The phenomenon of unaffected males transmitting the disorder could be due to an autosomal suppressor systeme. Our findings indicate that male transmission may be important for the frequency of the disorder.

Adolescent↗
PubMed1983

Frequency of fragile X chromosomes, fra(X), in lymphocytes in relation to blood storage time and culture techniques.

The fra(X) frequencies in metaphases of lymphocytes from seven male patients with X-linked mental retardation and macroorchidism were scored after use of different culture techniques and different times of blood storage. No statistically significant differences were found between the fra(X) rates of lymphocytes grown either in folic acid deficient medium (TC 199) or in medium containing folic acid as well as a folic acid antagonist (methotrexate: MTX, aminopterine: AP). With respect to the effect of the time interval between blood sampling and culture set-up, a statistically significant decrease in the fra(X) frequency was observed in all culture types after 4 or 7 days of blood storage.

Blood Preservation↗
PubMed1983

Down's syndrome in the male. Reproductive pathology and meiotic studies.

Studies on testicular histology and meiosis were carried out by the use of light and electron microscopy in an 18-year-old Down's syndrome male in an attempt to follow the fate of the extra chromosome 21 and to evaluate the effects of this condition on spermatogenesis and the reproductive functions. The histological changes in the testes corresponded to spermatogenic arrest. Electron microscopic whole-mount spreadings of meiotic cells in the pachytene stage showed that in most nuclei an extra chromosome 21 was not detectable. Only in a small number of nuclei, univalents or trivalents with segmental pairing structures of an extra chromosome could be discovered. In contrast, the great majority of (C-banded) diakinesis figures showed the presence of a supernumerary G (no. 21) chromosome. The absence of a traceable extra chromosome 21 in most pachytene cells is explained by the assumption that it is intimately connected with and hidden in the sex vesicle, whose complex structure does not allow the identification of single elements. Strong support for this assumption is seen (a) in the general tendency of narrow spatial association of unpaired segments with the XY complex and (b) in close structural similarities occurring between univalents or nonsynapsed segments of trivalents and the nonpaired segments of the sex chromosomes. It is suggested that the association or connection of an extra chromosome with the XY complex during pachytene interferes with the phenomenon of X inactivation. In animal systems such abnormal interference is related with spermatogenic breakdown and, in a general way, with male hybrid type sterility. So far, the range of sterility vs. fertility in cases of male Down's syndrome is not yet fully clear, but it appears that impairment of fertility, and sterility are most frequent. If so, it is proposed that the effect of the trisomy 21 condition on spermatogenesis (and fertility) is a consequence of the behavior of the extra chromosome in the meiotic prophase.

Adolescent↗
PubMed1983

Screening for fra(X)(q) in a population of mentally retarded males.

Among 242 institutionalized mentally retarded males in Northern Germany screened for fra(X)(q), 15 (6.2%) with severe mental retardation expressing fra(X)(q) were detected. One patient displayed Klinefelter's syndrome in addition. All fra(X)(q) males showed the typical facial signs, but three of the adults did not express macroorchidism. A preliminary estimation of an overall frequency of 1:2000 males for the fra(X)(q) condition is suggested.

Adolescent↗
PubMed1982

[Cytogenetic, gynaecological and sonographic aspects of twin pregnancy with parental Robertsonian translocation 13/14 (author's transl)].

A prenatal chromosome analysis for a parental Robertsonian translocation 13/14 is absolutely imperative. In the present case of a twin pregnancy, it was possible to present the chromosome complement of only one foetus. Since this foetus showed the Robertsonian translocation in the same form as the phenotypically healthy mother, and since the ultrasound findings were normal, it was concluded that foetus I was normal. Further measures for the cytogenetic analysis of foetus II were abandoned after the first amniotic sample could not be analysed. At the time of the amniocentesis this child was retarded when compared to foetus I. Since the life expectancy of a possibly chromosomally unbalanced child is slight, it was not necessary for the parents to take further steps. During the rest of the pregnancy however, this difference in the development of the children evened out unexpectedly and two phenotypically healthy children were born. The implications of a delayed growth rate as an indication of abnormal foetal development are discussed.

Adult↗
PubMed1982

Clinical, endocrinological, and cytological characterization of two 46, XX males.

In two 46,XX males, 20 and 21 yr of age, gonadotropins, testosterone, and estradiol were measured in serum and compared to those in a control group of four men. In addition, in one subject, androgen metabolism was measured in biopsied skin and cultured skin fibroblasts. In both XX men, a pulsatile pattern of gonadotropin, testosterone, and estradiol release into serum was observed. The levels of the gonadotropins and estradiol were higher and the levels of testosterone were lower in XX men than in normal men. hCG stimulation resulted in a significant increase in testosterone secretion, and LRH administration caused a more prolonged rise in gonadotropin levels in the XX men. The administration of estradiol caused a positive feedback response in the XX men and resulted in a suppression of gonadotropin secretion in the controls. Finally, the formations of C-19 metabolites from testosterone and estrone from androstenedione were found to be in the same range in skin and skin fibroblasts from the XX men as in those from normal men. It can be concluded that 46,XX men have altered hypothalamic-pituitary and gonadal function compared to normal men.

Adult↗