46,XX/46,XX,8p- mosaicism in a phenotypically normal female

A phenotypically normal female was found to have a chromosome 8 short arm deletion in a low percentage of the cells. The reduced proportion of monosomic cells in relationship with proband's age are discussed.     

Chimerism 46,XX/46,XY in a phenotypic female

Summary A female patient is reported with lymphocyte chromosome chimerism (46,XX/46,XY). Her whole-body chimerism was confirmed in the AB0 blood group system by the presence of two different erythrycyte populations, A₁0 and 00. Normal findings were recorded at physical and gynecological examination, except for mammary hypoplasia and sterility of 7 years duration, the latter complaint being the cause for genetic examination of the patient.     

A case of 46,XY/45,X/46,XX intersex

Summary A case of 46,XY/45,X/46,XX mosaicism in a phenotypic intersex is decribed in detail. A few relevant aspects, which emerge especially from the phenotypic and karyotypic analysis, are briefly commented upon.

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Zusammenfassung Es wird ein Fall von Mosaicismus 46,XY/45,X/46,XX beschrieben. Einige Aspekte, die aus der phänotypischen und karyotypischen Analyse des Patienten hervorgehen, sind kurz kommentiert.

     

Cytogenetic analysis of somatic and germinal cells from 38,XX/38,XY phenotypically normal boars

Many chromosomal abnormalities have been reported to date in pigs. Most of them have been balanced structural rearrangements, especially reciprocal translocations. A few cases of XY/XX chimerism have also been diagnosed within the national systematic chromosomal control program of young purebred boars carried out in France. Until now, this kind of chromosomal abnormality has been mainly reported in intersex individuals. We investigated 38,XY/38,XX boars presenting apparently normal phenotypes to evaluate the potential effects of this particular chromosomal constitution on their reproductive performance. To do this, we analyzed (1) the chromosomal constitution of cells from different organs in one boar; (2) the aneuploidy rates for chromosomes X, Y, and 13 in sperm nuclei sampled from seven XY/XX boars. 2n = 38,XX cells were identified in different nonhematopoietic tissues including testis (frequency, <8%). Similar aneuploidy rates were observed in the sperm nuclei of XY/XX and normal individuals (controls). Altogether, these results suggest that the presence of XX cells had no or only a very limited effect on the reproduction abilities of the analyzed boars.     

Investigation of genetic markers in a true Hermaphrodite with chi 46,XX/46,XY

Summary We documented a new case of chi 46,XX/46,XY true hermaphroditism substantiated by the evaluation of chromosomal heteromorphism in banded preparations. The patient, a 12-year-old Japanese boy with ambiguous external genitalia, was seen because of abnormal breast development. Surgical exploration showed the right gonad to be an ovotestis and the left gonad to be an ovary. Cytogenetic studies revealed cell admixtures of 46,XX and 46,XY karyotypes in peripheral lymphocytes, skin fibroblasts, and gonadal fibroblasts. From the pedigree studies, the paternal double genetic contributions were evidenced by the differences of sex chromosomes and the blood group types for the ABO and MNSs systems in the two cell lines of the patient. The maternal double genetic contributions were confirmed by the inheritance of Q-fluorescent markers on chromosomes 13 and 22 and by alleles for the Kidd blood group system.     

Demonstration of spontaneous XX/XY chimerism by DNA fingerprinting

Summary The M13 bacteriophage probe, which makes possible the establishment of DNA fingerprints, was used to study a phenotypically normal woman with a 46XY karyotype and her twin brother. Identical fingerprints and positive hybridzation with a series of Y-specific probes were obtained on blood samples from the siblings. DNA from a skin biopsy of the woman yielded a clearly different pattern and displayed no Y-specific hybridization, indicating that she is a spontaneous chimera. This study illustrates the use of DNA fingerprinting as a powerful and simple aid to the diagnosis of natural chimerism.     

Polymorphic detection of a parthenogenetic maternal and double paternal contribution to a 46,XX/46,XY hermaphrodite.

True hermaphroditism in humans usually is associated with a 46,XX karyotype or with mosaicism in which admixtures of cells with an XX and an XY karyotype are seen. However, the mechanisms that cause such mosaicisms are poorly understood. To date, with rare exceptions, analyses of hermaphrodites have been limited mostly to cytogenetic investigations. In this report, we describe a 5-year-old patient with true hermaphroditism and a 46,XX/46,XY karyotype (ratio 38:12) in lymphocytes, suggesting involvement of two fertilization events. Microsatellite DNA polymorphisms distributed throughout the genome were analyzed, to investigate the origin of the cell lines concerned. The results are consistent with double paternal and single maternal genetic contributions. Possible mechanisms that would explain these findings are discussed. The most likely mechanism involves a single haploid ovum dividing parthenogenetically into two haploid ova, followed by double fertilization and fusion of the two zygotes into a single individual, at the early embryonic stage.     

Klinefelter's syndrome, mosaic 46,XX/46,XY/47,XXY/48,XXXY/48,XXYY: a case report

A 35-year-old male was investigated for primary infertility. Clinical examination showed an intelligent man with normal facial appearance and moustache and small firm testes. Testicular histopathology revealed marked atrophy of the testes with no spermatogenesis and absence of germ cells. Hormonal profile showed elevated levels of FSH,LH and low levels of testosterone. Chromosome analysis from whole blood culture showed cells with 46,XX/46,XY/47,XXY/48,XXXY/48,XXYY mosaicism. The predominant cell line was 47,XXY (87.86%). 46,XY/47,XXY mosaicism is not uncommon. However, mosaicism of multiple sex chromosome aneuploidy is rarely observed. This is the first report of mosaicism in Klinefelter's syndrome variant with five cell lines.     

60,XY/60,XX chimerism in the germ cell line of mature bulls born in heterosexual twinning

According to present knowledge there is a germ cell chimerism (XY/XX) in young bulls born in heterosexual twinning due to exchange of primordial germ cells in embryonic life. These germ cells were believed to have been eliminated in the young bull. Two-color fluorescence in situ hybridization (FISH) identification of the sex chromosomes by biotinylated and digoxygenin labeled probes have been used. The material consisted of three bulls born in heterosexual twinning. The results obtained indicated that even mature bulls (more than two years old) demonstrate spermatogonial chimerism. Several authors state that the bulls with blood cell chimerism, originating from dizygous twinning, are characterized by decreased fertility. Changes of the sex ratio of offspring due to proliferation of the female cells have also been proposed. The present observations should give a renewed interest in checking the possibility of survival and differentiation of germ cells from the female partner in the germ cell lines.     

Cri du Chat-syndrome mit Chromosomenmosaik 46, XY/46, XY, 5p-

Summary The case of a 2;5 year old boy with the typical features of the Cri du Chatsyndrome is described. The cytogenetical examination of lymphocytes and fibroblasts revealed a mosaicism with an approximated 1:1 relation between normal cells and cells with a deletion of the short arm of a B-chromosome. Autoradiography proved the deleted chromosome to be a chromosome No. 5.     

New cytogenetic variant of Orbeli's syndrome (46,XY/45,XY,-D/46,XY,Dq+)

Summary A newborn child with multiple congenital abnormalities, including severe hypoplastic thumb and atresia recti, is described. The cytogenetic analysis revealed a mosaicism 46,XY/45,XY,-D/46,XY,Dq+. The combination of mosaic D-monosomy and two cardinal features of 13q-syndrome give the possibility to consider this case as new cytogenetical variant of the Orbeli's syndrome.

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Zusammenfassung Ein Neugeborenes mit multiplen kongenitalen Abnormitäten einschließ-lich erheblicher Hypoplasie der Daumen und Atresia recti wird beschrieben. Die cytogenetische Analyse ergab ein Mosaik 46,XY/45,XY,-D/46,XY,Dq+ Die Kombination von Mosaik D-Monosomie und den zwei Hauptsymptomen des 13q-Syndroms läßt in diesem Falle eine neue cytogenetische Variante des Orbeli-Syndroms vermuten.

     

In vivo and in vitro studies in a 46, XY phenotypically female infant with 17-ketosteroid reductase deficiency

A 46, XY phenotypically female infant with 17-ketosteroid reductase (17-KSR) showed normal plasma androgens for chromosomal sex shortly after birth, but did not show the physiologic testosterone rise. One intramuscular injection with human chorionic gonadotropin resulted in high ratios between androstenedione/testosterone and dehydroepiandrosterone/delta 5-androstenediol, confirming the diagnosis. In spermatic vein plasma similarly elevated ratios were found. A urinary steroid profile revealed elevated levels of metabolites of 17-OH-progesterone and androstenedione. In vitro studies in testicular tissue showed a decreased capacity of 17-ketosteroid reductase, the reduction capacity being more affected than the oxidation capacity. The activity of 3 beta-hydroxysteroid-dehydrogenase was slightly increased. The serial analysis of plasma androgens provides more insight in the natural history of 17-ketosteroid reductase.