Molecular genetic studies of complete hydatidiform moles

Whole genome uniparental isodisomy detected using single nucleotide polymorphism (SNP) microarray in molar pregnancy: a case report

BACKGROUND

Gestational trophoblastic neoplasms consist of complete and partial hydatidiform moles, both of which are considered aberrant conceptuses. Both conditions, complete hydatidiform mole (CHM) and partial hydatidiform mole (PHM), differ in histological characteristics, genetic origin and content and clinical features. CHM have a diploid karyotype, mostly 46,XX but lack maternal genetic contribution with all chromosomes of paternal origin. High-resolution SNP microarray testing is an efficient method used to determine the parental contribution of the genomic material in molar pregnancies and confirm the diagnosis.

CASE PRESENTATION

We present a case of CHM in a 43-year-old, G3P2Ab1 who presented to the emergency department with 2 episodes of heavy bleeding. Chromosome analysis showed a normal 46,XX karyotype but with a homozygous pericentric inversion on chromosome 9. High-resolution SNP microarray studies detected whole genome uniparental isodisomy.

CONCLUSION

We present a case of CHM with homozygous pericentric inversion on chromosome 9 and whole genome uniparental isodisomy. This case illustrates the efficacy of high-resolution SNP microarray in confirming the diagnosis of CHM.

Overcoming challenges associated with broad sharing of human genomic data

Since the Human Genome Project, the consensus position in genomics has been that data should be shared widely to achieve the greatest societal benefit. This position relies on imprecise definitions of the concept of 'broad data sharing'. Accordingly, the implementation of data sharing varies among landmark genomic studies. In this Perspective, we identify definitions of broad that have been used interchangeably, despite their distinct implications. We further offer a framework with clarified concepts for genomic data sharing and probe six examples in genomics that produced public data. Finally, we articulate three challenges. First, we explore the need to reinterpret the limits of general research use data. Second, we consider the governance of public data deposition from extant samples. Third, we ask whether, in light of changing concepts of broad, participants should be encouraged to share their status as participants publicly or not. Each of these challenges is followed with recommendations.

Enhancing Clinical Applications by Evaluation of Sensitivity and Specificity in Whole Exome Sequencing

The cost-effectiveness of whole exome sequencing (WES) remains controversial due to variant call variability, necessitating sensitivity and specificity evaluation. WES was performed by three companies (AA, BB, and CC) using reference standards composed of DNA from hydatidiform mole and individual blood at various ratios. Sensitivity was assessed by the detection rate of null-homozygote (N-H) alleles at expected variant allelic fractions, while false positive (FP) errors were counted for unexpected alleles. Sensitivity was approximately 20% for in-house results from BB and CC and around 5% for AA. Dynamic Read Analysis for GENomics (DRAGEN) analyses identified 1.34 to 1.71 times more variants, detecting over 96% of in-house variants, with sensitivity for common variants increasing to 5%. In-house FP errors varied significantly among companies (up to 13.97 times), while DRAGEN minimized this variation. Despite DRAGEN showing higher FP errors for BB and CC, the increased sensitivity highlights the importance of effective bioinformatic conditions. We also assessed the potential effects of target enrichment and proposed optimal cutoff values for the read depth and variant allele fraction in WES. Optimizing bioinformatic analysis based on sensitivity and specificity from reference standards can enhance variant detection and improve the clinical utility of WES.

Hydatidiform Mole Presents As Pregnancy in a 48-Year-Old Perimenopausal Female: A Case Study

Pregnancy should be suspected whenever a woman in her childbearing years misses a menstrual period. Clinical suspicion is increased if she also reports any sexual activity while not using contraception or is inconsistent in her use of contraception. Laboratory findings that aid in the diagnosis of pregnancy include the detection of human chorionic gonadotropin (hCG) in blood or urine. Hydatidiform mole (HM) is part of a group of diseases classified under gestational trophoblastic disease (GTD), which originate in the placenta and have the potential to locally invade the uterus and metastasize. Although molar pregnancies are designated as benign, they have the potential to develop into a malignancy. In this case study, we present a 48-year-old peri-menopausal female patient, with a 1+ year history of irregular menses, who presented to the clinic with signs and symptoms of pregnancy, unprotected sexual activity, and a positive at-home pregnancy test. Upon further workup of the patient, it was diagnosed that the patient had a hydatidiform molar pregnancy. It is interesting to note that benign gestational trophoblastic diseases generally occur in younger women, of “reproductive age” (generally in their twenties to early thirties), and is extremely rare in peri- and post-menopausal women.

The Contribution of QF-PCR and Pathology Studies in the Diagnosis of Diandric Triploidy/Partial Mole

Objective: the aim of our study was to assess the contribution of quantitative fluorescent polymerase chain reaction (QF-PCR) and pathology studies in the diagnosis of diandric triploidies/partial hydatidiform moles. Methods: this study included all fet al triploidies diagnosed by QF-PCR in chorionic villi or amniotic fluid in the 2 centers of BCNatal in which a maternal saliva sample was used to establish its parental origin. Pathology studies were performed in products of conception and concordance between a partial hydatidiform mole diagnosis and the finding of a diandric triploidy was assessed. Results: among 46 fetal triploidies, found in 13 ongoing pregnancies and in 33 miscarriages, there were 26 (56%) diandric triploidies. Concordant molecular (diandric triploidy) and pathology results (partial mole) were achieved in 14 cases (54%), while in 6 cases (23%) pathology studies were normal, and in the remaining 6 cases (23%) pathology studies could not be performed because miscarriage was managed medically. Conclusions: diandric triploidy is associated with partial hydatidiform mole and its diagnosis is crucial to prevent the development of persistent trophoblastic disease. QF-PCR analysis in chorionic villi or amniotic fluid provides a more accurate diagnosis of the parental origin of triploidy than the classical pathology studies.

Hydatidiform Mole in a Patient With a Concern for Neoplasia: A Case Report

Molar pregnancy or a hydatidiform mole, also referred to as gestational trophoblastic disease, is an abnormal type of pregnancy, in which a potentially anomalous egg is abnormally fertilized resulting in a subsequently non-viable conceptus becoming an enlarged growth in the uterus with dangerous complications. These moles can occur as either complete or partial moles, each with its own unique features. In this article, we report a case of a pregnant woman who presented to her primary care doctor with the chief complaint of shortness of breath. Upon further questioning, she was found to have slight vaginal bleeding. Further workup of the unexplained bleeding revealed a small, yet concerning molar pregnancy, and led to our encounter with the patient on her operating day for a dilation and curettage. As these moles are somewhat rare occurrences, this case report aims to describe the condition, with a focus on management and outcomes.

NLRP7 is expressed in the ovine ovary and associated with in vitro pre-implantation embryo development

NLRP (NACHT, LRR and PYD domain-containing proteins) family plays pivotal roles in mammalian reproduction. Mutation of NLRP7 is often associated with human recurrent hydatidiform moles. Few studies regarding the functions of NLRP7 have been performed in other mammalian species rather than humans. In the current study, for the first time, the function of NLRP7 has been explored in ovine ovary. NLRP7 protein was mainly located in ovarian follicles and in in vitro pre-implantation embryos. To identify its origin, 763 bp partial CDS of NLRP7 deriving from sheep cumulus oocyte complexes (COCs) was cloned, it showed a great homology with Homo sapiens. The high levels of mRNA and protein of NLRP7 were steadily expressed in oocytes, parthenogenetic embryos or IVF embryos. NLRP7 knockdown by the combination of siRNA and shRNA jeopardized both the parthenogenetic and IVF embryo development. These results strongly suggest that NLRP7 plays an important role in ovine reproduction. The potential mechanisms of NLRP7 will be fully investigated in the future.

Dysregulation of Placental Functions and Immune Pathways in Complete Hydatidiform Moles

Gene expression studies of molar pregnancy have been limited to a small number of candidate loci. We analyzed high-dimensional RNA and protein data to characterize molecular features of complete hydatidiform moles (CHMs) and corresponding pathologic pathways. CHMs and first trimester placentas were collected, histopathologically examined, then flash-frozen or paraffin-embedded. Frozen CHMs and control placentas were subjected to RNA-Seq, with resulting data and published placental RNA-Seq data subjected to bioinformatics analyses. Paraffin-embedded tissues from CHMs and control placentas were used for tissue microarray (TMA) construction, immunohistochemistry, and immunoscoring for galectin-14. Of the 14,022 protein-coding genes expressed in all samples, 3,729 were differentially expressed (DE) in CHMs, of which 72% were up-regulated. DE genes were enriched in placenta-specific genes (OR = 1.88, p = 0.0001), of which 79% were down-regulated, imprinted genes (OR = 2.38, p = 1.54 × 10-6), and immune genes (OR = 1.82, p = 7.34 × 10-18), of which 73% were up-regulated. DNA methylation-related enzymes and histone demethylases were dysregulated. "Cytokine-cytokine receptor interaction" was the most impacted of 38 dysregulated pathways, among which 17 were immune-related pathways. TMA-based immunoscoring validated the lower expression of galectin-14 in CHM. In conclusion, placental functions were down-regulated, imprinted gene expression was altered, and immune pathways were activated, indicating complex dysregulation of placental developmental and immune processes in CHMs.

Recurrent complete hydatidiform mole: where we are, is there a safe gestational horizon? Opinion and mini-review

Benign hydatidiform mole, complete or partial, is the most common type of gestational trophoblastic disease (GTD) characterised by excessive trophoblastic proliferation and abnormal embryonic development. Although most complete hydatidiform moles (CHMs) are diploid androgenetic, a few cases of CHMs are biparental, characterised by recurrence and familial clustering. In these rare cases, mutations in NLRP7 or KHDC3L genes, associated with maternal imprinting defects, have been implicated. Current data regarding future pregnancy options in hydatidiform moles are discussed and our opinion is presented based on an incidence that took place in our hospital with a woman with consecutive molar pregnancies. In recurrent hydatidiform moles, DNA testing should be performed and when NLRP7 or KHDC3L mutation are detected, oocyte donation should be proposed as an option to maximise woman's chances of having a normal pregnancy.

Molecular and Immunohistochemical Characteristics of Complete Hydatidiform Moles

Molar pregnancy is a gestational trophoblastic disease that belongs to the category of precancerous lesions. On the other end of the spectrum are gestational trophoblastic neoplasms such as invasive mole, choriocarcinoma, placental site trophoblastic tumor and epithelioid trophoblastic tumor, which are considered malignant tumors. Based on defined histopathological criteria, molar pregnancy is divided into partial and complete hydatidiform mole. Especially in the case of early complete mole, the diagnosis can be quite challenging and often necessitates additional molecular or immunohistochemical methods. The aim of this study was to assess the importance of additional molecular and immunohistochemical methods to accurately diagnose complete hydatidiform mole and to stress the importance of correct diagnosis and close follow-up of these patients. A total of 367 consecutive cases of spontaneous abortion were analyzed in a 3-year period. Eight cases with histopathological diagnosis of complete molar pregnancy were selected for further analysis. Apart from standard microscopic analysis, additional molecular and immunohistochemical analyses were performed in all eight cases. Most of the histopathological characteristics of complete molar pregnancy were present in all cases, together with complete absence of positivity for the p57 immunohistochemical marker in the cytotrophoblasts and villous stromal cells. The molecular analysis revealed androgenetic diploidy in seven cases and biparental diploidy in one case with more than three consecutive complete molar pregnancies. Additional immunohistochemical and molecular methods can considerably aid in the correct diagnosis of molar pregnancy.