RESUMO
Triploidy is the presence of an extra haploid set of chromosomes and can exist in complete or mosaic form. The extra haploid set of chromosomes in triploid cells can be of maternal or paternal origin. Diploid/triploid mixoploidy is a unique form of triploid mosaicism that requires the aberrant segregation of entire parental genomes into distinct blastomere lineages (heterogoneic cell division) at the earliest zygotic divisions. Here we report on eight cases of diploid/triploid mixoploidy from our institution and conduct a comprehensive review of the literature. The parental origin of the extra set of chromosomes was determined in two cases; and, based on phenotypic evidence we propose the parental origin in the other cases. One case with complex mixoploidy appears to have a digynic origin in addition to the involvement of two different sperm. Of our eight cases, only one resulted in the birth of a live healthy child. The other pregnancies ended in miscarriage, elective termination of pregnancy, intrauterine fetal demise or neonatal death. A review of the literature and the results of our cases show that a preponderance of recognized cases of diploid/triploid mixoploidy has a digynic origin.
Assuntos
Diploide , Genômica , Mosaicismo , Triploidia , Zigoto , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Aborto Espontâneo/genética , Biomarcadores , Biópsia , Blastômeros , Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/genética , Inibidor de Quinase Dependente de Ciclina p57/genética , Inibidor de Quinase Dependente de Ciclina p57/metabolismo , Análise Citogenética , Feminino , Estudo de Associação Genômica Ampla/métodos , Genômica/métodos , Humanos , Imuno-Histoquímica , Repetições de Microssatélites , Fenótipo , Polimorfismo de Nucleotídeo Único , GravidezRESUMO
OBJECTIVE: To simultaneously evaluate the p57(KIP2) antibody expression and genotype of individual cells from paraffin sections of molar pregnancies. STUDY DESIGN: Paraffin sections from 10 typical and unusual molar pregnancies were evaluated with the FICTION technique (Fluorescence Immunophenotyping and Interphase Cytogenetics as a Tool for the Investigation of Neoplasms), using immunofluorescence staining for the p57(KIP2) antibody and enumeration fluorescence in situ hybridization (FISH) probes. The unusual cases included androgenetic/ biparental chimeric complete hydatidiform moles (CHM) and mosaic partial hydatidiform moles (PHM). The unusual molar conceptions provided insight into interpreting atypical p57(KIP2) staining patterns and identifying androgenetic cells. RESULTS: The androgenetic/biparental chimeric CHMs demonstrated a negative p57(KIP2) Staining pattern for the androgenetic cells and positive staining for the biparental cells. Concordantly, the FISH results showed delineation between the androgenetic cells and the biparental cells, indicating 2 distinct genotypes. Also, in the 2 cases of mosaic PHM, the partial loss of p57(KIP2) antibody staining was due to mosaic loss of chromosome 11, assumed to be the maternal copy. This provides a biological explanation as to how false interpretation could occur when evaluating p57(KIP2) immunostaining results. CONCLUSION: The FICTION technique is a valuable ancillary tool for simultaneously evaluating the genotype and p57(KIP2) expression in unusual molar pregnancies.
