11/29. Edwards' syndrome after the replacement of cryopreserved-thawed embryos.A case of Edwards' syndrome after the replacement of frozen-thawed embryos is reported. The presence of cardiac abnormalities and limb deformities raised the suspicion of chromosomal abnormality. The diagnosis of trisomy 18 was made by cytogenetic analysis of fetal blood from the umbilical vein. The chromosomal nondisjunction might have been spontaneous or because of freezing and thawing. If it occurred as a result of freezing and thawing, it is more likely that this was at the first cleavage division rather than the second meiotic division because the embryos were frozen at the late pronuclear stage. Unfortunately, there were no karyotypic markers in the couple's chromosomes to time the nondisjunction. The wisdom of using donor oocytes in an ovum donation program from patients with long-standing infertility is questioned.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
12/29. Karyotypic characterization of a new human embryonal rhabdomyosarcoma cell line.Chromosomal analysis of an advanced recurrent rhabdomyosarcoma of the embryonal type was performed on cell cultures in the 9th passage of in vitro cultivation. This tumor showed a modal karyotype of 54 and was characterized by multiple numerical and structural chromosome abnormalities, all present in high frequencies. Abnormalities observed in 100% of the cells included a der(1) chromosome with a short unidentified insertion between q31 and q32; a der(1) chromosome, arising from insertion at the same breakpoint of a longer segment with a duplicated 1q31 band and translocation of 13q23 qter to 1p36, a deleted tetrasomic 13q23 qter, and a der(4) chromosome showing 1p36 pter translocated to 4p13. Other common abnormalities included trisomy of chromosomes 8, 13, and 9p, deletions of chromosomes 6, 10, 11, and 12, and presence of marker chromosomes. Characterization of the established line at the 38th passage evidenced the persistence of both the modal karyotype and all the numerical and structural abnormalities previously found. The results of this study provide further evidence of the major involvement of alterations in chromosome 1 in the progression of rhabdomyosarcoma.- - - - - - - - - - ranking = 0.83333333333333keywords = embryo (Clic here for more details about this article) |
13/29. X-linked ocular albinism. Characteristic pattern of affection in female carriers.The authors report on a family with X-linked ocular albinism. Examined were one of three affected males and eight females. Six women were carriers and showed iris retroillumination and typical abnormalities of the fundus. The patchy or striated hypopigmentation of the retinal pigment epithelium is thought to be due to random inactivation of the paternal or maternal X-chromosome respectively. The pattern of affection however represents a nonrandom embryological developmental pattern of the retinal pigment epithelium.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
14/29. Occurrence of holoprosencephaly in chromosome 13 disorders cannot be explained by duplication/deficiency of a single locus.Four cases of holoprosencephaly with duplication/deletion involving chromosome 13 are presented and additional cases are summarized from the literature. When examined as a series, the duplications (trisomy 13, trisomy 13pter q14) and deletions (deletion 13q12 qter, deletion 13q31 qter, ring 13 with deletion 13q14 qter) exclude deletion or duplication of single chromosome 13 bands as the cause for holoprosencephaly. Increased dosage of the 13pter q14 region relative to the 13q14 qter region as the cause is also ruled out by the duplication 13q21 qter cases reported in the literature. Altered timing of forebrain development, causing reversion to a more primitive embryonic and phylogenetic brain structure, is related to dosage imbalance of at least two chromosome 13 regions.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
15/29. Corneal involvement in autosomal dominant coloboma/microphthalmos.Peripheral corneal opacification in the line of closure of the embryonic fissure associated with hyperopic astigmatism and anisometropic amblyopia was identified in two eyes of two members of a family with isolated autosomal dominant coloboma-microphthalmos. A review of the literature disclosed no previously reported cases. It would appear that the gene for isolated coloboma-microphthalmos can affect the growth and differentiation of mesenchymal cells of neural crest origin, as well as the neuroectodermal tissues of the embryonic fissure.- - - - - - - - - - ranking = 0.33333333333333keywords = embryo (Clic here for more details about this article) |
16/29. Further observations of ocular pathology in Down's syndrome.We studied the eyes of two children with proven trisomy 21 and updated the microscopic ocular findings. The ocular malformations, generally of a minor nature, comprise a variety of nonspecific hyperplasia or hamartomata, hypoplasias, tissue defects and heterotopias, and involve virtually every portion of the globe. Ocular and extraocular abnormalities in Down's syndrome do not correlate well embryologically, cytogenetically or in regard to incidence or severity. The type of ocular anomalies usually encountered in trisomy 21 suggests that the globe was affected by the chromosomal anomaly rather late in its development.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
17/29. Turner's syndrome with sympathoblastoma.A case of Turner's syndrome clinically and cytogenetically diagnosed in a 15-year old girl is reported. At age 4 the girl was hospitalized for renal malformations (doubling of the urethra and its ectopic opening). Laparatomy revealed a small tumoral formation which was removed. The diagnosis established anatomo-histologically was of sympathoblastoma. Since the tumor is genetically conditioned by an autosomal mutation, association of the gonosomial anomaly and sympathoblastoma is supposed to be fortuitious though it is not improbable that the tumor be the result of an embryonar disorder favourized by the chromosomal anomaly.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
18/29. Peters' anomaly associated with partial deletion of the long arm of chromosome 11.A 5-week-old boy with Peters' anomaly was found to have an interstitial deletion of the long arm of chromosome 11; no developmental delays or dysmorphic features were evident. His right cornea was enlarged and opaque with extensive pannus formation; the anterior chamber, iris, and lens were not visible. The left eye showed a central opacity and a superficial pannus; the optic disk and macula could not be visualized. He underwent bilateral corneal transplantation. Histologic examination of the corneal buttons confirmed the diagnosis. The potential genetic mechanisms in this case included a gene for this autosomal recessive disorder on the long arm of chromosome 11, generalized disruption of the embryogenesis of the anterior segment as a result of the deleted material, or simple autosomal recessive inheritance unrelated to the chromosomal deletion.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
19/29. Human chromosome 2 rod/ring mosaicism: probable origin by prezygotic breakage and intrachromosomal exchange.A 5-year-old male with mild mental retardation showed a chromosomal rearrangement involving duplication of part of 2q (2q33.3 leads to 2wter) in 70% of metaphases from peripheral blood; the remaining 30% of cells had a rearrangement of chromosome 2 in the form of a ring, viz., r(2)(2p25.2 leads to 2q33.2). Both configurations appeared to be missing a tiny portion of 2p (p25.3 leads to pter). All metaphases examined from cultured skin fibroblasts from the child had the abnormal rod configuration of chromosome 2; none had the ring. The pattern of the 2q duplication/2p deletion in the rod is that expected if there were an inversion in a No. 2 in one of the parents. Q-, G-, and R-banding studies, however, revealed both parents to be chromosomally normal. Furthermore, the finding of an inversion would not explain the origin of the ring. The most probable explanation is that neither parent is mosaic for an inversion, but that the rod and ring configurations arose simultaneously from a de novo, prezygotic or early zygotic exchange in a No. 2, either between complementary dna strands in G1 or by intrachromosomal exchange in S or G2. Differential selection against cells with the ring chromosome in blood and skin probably occurred during subsequent embryological development. Cytoplasmic malate dehydrogenase (MDH1) was excluded from the terminal band of 2p (i.e., 2p25.3) by deletion mapping.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
20/29. Multiple active X chromosomes in myelofibrosis with myeloid metaplasia.A woman with myelofibrosis and myeloid metaplasia had a karyotype of 47,X,del(X)(q22), del(X)(q22) in unstimulated peripheral blood and bone marrow aspirate cultures. The normal X chromosome was late replicating, and the two deleted X chromosomes always replicated early and synchronously. The karyotype from phytohemagglutin-stimulated peripheral blood cultures was uniformly 46,XX. Structurally abnormal X chromosomes are exceedingly rare in myeloproliferative disease. The abnormal karyotype very likely reflects monoclonal proliferation of an abnormal myeloid cell line. The x chromosome inactivation process, which acts upon embryonic somatic cells of all mammals, apparently does not react to postembryonic nondisjunction of the active X chromosome.- - - - - - - - - - ranking = 0.33333333333333keywords = embryo (Clic here for more details about this article) |
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