In this review, we summarized the results of experimental and clinical studies about three human endogenous retroviruses and their products—syncytin-1, syncytin-2, and suppressyn in human physiology and pathophysiology. We summed up the described connection with various pathological processes and diseases, mainly with pregnancy-induced hypertensive diseases such as preeclampsia, oncogenesis, gestational trophoblastic disease, and multiple sclerosis. Supposed mechanisms of action and the potential of clinical applications are also described.

Objective: This short communication demonstrates how short tandem repeat genotyping can identify the origin of gestational choriocarcinoma. Materials and methods The origin of gestational choriocarcinoma in our three cases was determined using the short tandem repeats genotyping technique, which involved quantitative fluorescent PCR and fragmentation analysis. Results: In Case 1 despite no medical history of molar pregnancy , DNA analysis indicated that the choriocarcinoma originated from a homozygous complete hydatidiform mole. We conclude, that the patient's complete abortion 10 years prior to the choriocarcinoma diagnosis was an undiagnosed complete hydatidiform mole. In Case 2 and Case 3 the clinically presumed origin of choriocarcinoma was confirmed. Conclusion: Determining the origin of choriocarcinoma is essential for clinical application, as it affects the FIGO scoring system for gestational trophoblastic neoplasia, which determines the patient's prognosis and treatment approach.

A case of double trisomy 16 and 22 in the second pregnancy loss is presented. DNA analyses (short tandem repeats genotyping) of miscarriage specimen was indicated because of ultrasound suspicion of partial hydatidiform mole. After the partial hydatidiform mole exclusion, further DNA analyses focused on the most common aneuploidies causing pregnancy loss, detected double trisomy 16 and 22 in the product of conception. The couple was referred to clinical genetic consultation and normal parental karyotypes were proved. For further explanatory purposes, archived material from the first pregnancy loss was analyzed and trisomy of chromosome 18 was detected. By comparison of allelic profiles of the mother, father, and both losses, the maternal origin of all aneuploidies was proven what can be attributed to frequent meiosis errors, probably due to advanced maternal age (44 years at the first loss and 45 years at the second loss). In conclusion, aneuploidies can mimic partial hydatidiform mole. Genetic analysis is helpful on the one hand to rule out partial hydatidiform mole and on the other hand to identify aneuploidies and in this way to determine the cause of miscarriage.

The authors present a case of a partial hydatidiform mole where DNA analysis (STR - short tandem repeat genotyping) showed a triandric monogynic tetraploid genome composition with a XXXY gonosomal complement. This genetic finding clinicopathologically correlates with a partial hydatidiform mole, although it is rare in comparison with the typical, diandric monogynic triploid partial moles. The genetic analysis definitively confirmed the suspected dia gnosis of a partial mole. To exclude the possibility that molar pregnancy represented retained products of conception after elective pregnancy termination, STR profiles from molar pregnancy and previous products of conception were compared. Short tandem repeats genotyping is a useful molecular genetic method in the differential dia gnosis of partial hydatidiform moles, where clinical-pathological findings are frequently ambiguous.

Introduction: Gestational trophoblastic neoplasia (GTN) represents the malignant variant of gestational trophoblastic disease (GTD), a rare condition characterized by abnormal trophoblastic cell proliferation. GTN affects mostly women of reproductive age and is characterized by early metastatic progression. The majority of GTN tumors respond well to chemotherapy. The overall cure rate may be as high as 95 to 100 percent. Future pregnancy after treatment is an important issue. The purpose of this study was to analyze reproductive outcomes of GTN patients registered at the Center for GTD of Slovakia. Methods: A retrospective analysis of pregnancy outcomes in GTN patients after treatment. The study included all recorded pregnancies in GTN patients treated with systemic therapy at the Center for GTD of Slovakia in 1993–2024. Results: A total of 94 pregnancies in 51 patients were included. 44 patients (86.3%) were treated with single-agent chemotherapy and 7 (13.7%) with multi-agent chemotherapy. 41 patients (80.4%) had at least one pregnancy resulting in live birth. Of the 94 pregnancies, 61 (64.9%) resulted in live birth and 17 (18.1%) in miscarriage. Women after single-agent chemotherapy had more live births than women after multi-agent chemotherapy (68.7% vs. 36.4%, p = 0.035). Pregnancies conceived ≥ 12 months after finishing treatment resulted in more live births (25 vs 2; p = 0.004) and less pregnancy terminations (2 vs 8; p < 0.001) compared to those conceived earlier. Conclusion: GTN patients can expect a normal course of subsequent pregnancy after treatment with comparable outcomes to the general population.

The authors present a case of 1st trimester miscarriage where an early, complete hydatidiform mole was clinically suspected. Histopathological and immunohistochemical analyses excluded a complete mole, but the histomorphological profile was in concordance with a partial hydatidiform mole. Genetic analysis excluded a partial mole based on biparental genome composition, where further genetic analyses detected trisomy of chromosome 16. Trisomy of chromosome 16 is a frequent cause of 1st trimester abortions and may lead to highly abnormal placental histomorphology mimicking a partial mole. Genetic analyses are crucial for proper differential diagnosis and for the determination of adequate follow-up and prognosis for further pregnancies. Key words: trisomy 16 – aneuploidy – DNA analysis – placental histomorphology