Phenotypic expression of lethal chromosomal anomalies in human abortuses

Abstract

From anatomical and cytogenetic studies of 1500 spontaneous abortuses attempts were made to establish correlations between the phenotype and karyotype of the specimens. The criteria used to determine the phenotype were based on estimated developmental age and macroscopic and microscopic examinations of embryo and placenta. Main features were described permitting, on anatomic examination of the conceptus, diagnosis of genetic anomalies, and in some instances possibly assigning the type of chromosomal aberration: viz., in monosomy X, triploidies, tetraploidies, and some trisomies. Phenotypic expression at the cellular level was studied by morphometry of the placenta and by study of in-vitro growth charcteristics of cells lines initiated from aneuploid embryos. Study of growth rate characteristics may reveal the basis for the pathogenesis of developmental arrests.

Age of Gestation (Size) at Embryonic Demise: Taiíoring Counseling for Lethal versus Potentially Viable Aneuploidy

“…Moreover, all cases diagnosed as 'blighted ovum' were affected by aneuploidy that never occurs in viable gestations. These findings are in accor dance with previous studies [4][5][6]. Some tri somies (i.e., trisomy 1) are not observed even in abortion material and probably cause loss of the conceptus before pregnancy is recog nized.…”

“…There are few reports that correlate length of gestation with specific types of chromo some anomalies [4,5], and even fewer that correlate ultrasound findings of early fetal demise and chromosomal aberrations [6]. In this study we expand our analysis of the effect of different chromosome anomalies diag nosed by postmortem CVS on the length and ultrasonographic morphology of gestation.…”

Generalized abnormal embryonic development in missed abortion: Embryoscopic and cytogenetic findings

“…Some of the observed trisomies (trisomies 3, 6, and 12) are usually categorized as rare, with a low frequency of 0.2-1% [Warburton et al, 1980]. It has been postulated that these rare trisomies usually result in anembryonic sacs, the most severe degree of embryonic GD [Boué et al, 1976]. Although our study was limited to abortuses with ultrasono- Based on the CRL the head of the GD4 embryo is too small and the limb buds are profoundly retarded in development.…”

Prophase I Mouse Oocytes Are Deficient in the Ability to Respond to Fertilization by Decreasing Membrane Receptivity to Sperm and Establishing a Membrane Block to Polyspermy1

“…Triploidy occurs in ;1%-3% of all human conceptions [104][105][106], and diandric triploidy resulting from dispermic fertilization represents 60%-80% of triploids [104,[107][108][109][110]. Triploid conceptus material is detected in up to 30% of spontaneous abortions with embryonic aneuploidy [104,[107][108][109][111][112][113][114][115]. Also of interest in the cell biology of fertilization, recent data provide foundations for an evolving model of the role(s) of primary sperm-ZP binding in fertilization [116][117][118][119][120], and thus raise the possibility that multiple mechanisms contribute to prevent polyspermy, complementing the well-known actions of cortical granule release on the ZP [24,25].…”