# DNA sequencing of whole human cytomegalovirus genomes from formalin-fixed, paraffin-embedded tissues from congenital cytomegalovirus disease cases

## TL;DR

Researchers successfully sequenced the full genome of a virus causing congenital disease from preserved tissue samples, opening new possibilities for studying how genetic differences affect disease outcomes.

## Contribution

Demonstrated feasibility of sequencing whole HCMV genomes from FFPE tissues, expanding sample availability for genetic studies.

## Key findings

- Whole HCMV genomes were successfully sequenced from five cases using FFPE material.
- Two commercial DNA extraction kits were evaluated for FFPE HCMV sequencing.
- The study provides a pipeline for genome assembly and variant calling from FFPE samples.

## Abstract

Congenital cytomegalovirus disease (cCMV) is uncommon but can be severe. Investigations of the role of genome sequence variation in the causative virus (human cytomegalovirus, HCMV) in clinical outcome have to date depended on small sample numbers derived from fresh tissues. Extensive formalin-fixed, paraffin-embedded (FFPE) cCMV biorepositories established worldwide potentially provide much larger sample numbers for future investigations. However, there are no published reports of sequencing whole HCMV genomes from such material.

To sequence whole HCMV genomes from cCMV FFPE material

Sixteen FFPE samples of foetal kidney or placental tissue were processed from ten cCMV cases in foetuses or neonates. Two commercial kits for extracting DNA from FFPE material were evaluated, HCMV DNA was enriched in the extracts, and the samples were sequenced on the Illumina platform. The sequence read datasets were analysed by genotyping, genome assembly and variant calling using a published software pipeline.

Whole HCMV genomes were sequenced for five cases using either DNA extraction kit.

Sequencing whole HCMV genomes from cCMV FFPE material is feasible. This potentially facilitates future studies of the effects of HCMV variation on the clinical outcome of cCMV.