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Background: Considering the limited studies conducted on the possibility of vertical transmission of HHV-6 in humans at different stages of pregnancy, the objective of this research wasis to examine the vertical transmission of HHV-6 (human herpesvirus 6) in various tissues of aborted fetuses atduring different months of pregnancy.
Materials & Methods: This research was conducted on used 58 formalin- fixed paraffin- embedded tissues (FFPE) from 26 fetopsies. DNA extraction was performed using the phenol-chloroform technique. The quantity of extracted DNA samples was measured using the NanoDrop spectrophotometric method. PCR of the beta-globin gene confirmed the quality of the extracted DNA, and then the presence of the HHV-6 genome was tested using the Rreal-time PCR method.
Findings: Of the 26 fetuses examined, 22 (84.6%) were negative for HHV-6, and four (15.4%) were positive. All six first-trimester fetuses were negative. Among 13 second-trimester fetuses (29 FFPE tissues), two (7.7%) tested positive., wWhile none of the seven third-trimester fetuses (22 FFPE tissues) had placental positive placentasity. However, HHV-6 was detected in non-placental fetal tissues, including the liver of fetus No. 16 and the heart of fetus No. 22, both of which were in the third trimester.
Conclusion: These findings suggest that while vertical transmission of HHV-6 may occur, particularly in later stages of pregnancy andor in specific fetal tissues, the overall prevalence in theis sample studied was relatively low. Further investigation is needed to understand the implications of these results for maternal and fetal health.  
 

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Aims: Human herpes virus 6 (HHV-6) is a ubiquitous virus with a high rate of prevalence worldwide. In recent years, a new form of the virus genome has been identified called Chromosomally integrated HHV-6 (ciHHV-6). Further studies are required to elucidate the relation between ciHHV-6 and other clinical complications. The purpose of this study was to summarize the literature on different clinical aspects of the ciHHV-6 integration and its prevalevce in different communities.
Materials and methods: Search keywords include HHV-6, integrated genome, telomeric regions and integrated HHV-6. Scientific databases such as scopus, PubMed and google scholar with no specified start date were used for information collection.
Findings: About 1% of global populations are infected with ciHHV-6. Real-time PCR can be used to differentiate between ciHHV-6 and HHV-6 acute infection in which the viral load will be higher in ciHHV-6 compared to the acute infection. However, ciHHV-6 can be confirmed by evidence of one copy of viral DNA in hair or nail follicles. It has been shown that ciHHV-6 may disrupt the telomer stability.
Conclutions: To date, no treatment has been discovered to remove the viral genome from the host cells. Taken together, the integrated form of the HHV-6 genome could be linked to the various diseases, including heart and autoimmune diseases. But further studies are needed to find its association with other diseases in different geographic area.