21.04.21

Employees at Department of Clinical Genetics and Department of Molecular Medicine have been working hard to complete the first analyses of the whole human genome (photo: Tonny Foghmar).

Aarhus University Hospital has reached a milestone with completion of the first analyses of the whole human genome. The analyses are part of the collaboration within the Danish National Genome Center.

Doctors, molecular biologists and medical laboratory scientists at Aarhus University Hospital have just completed the first whole genome analyses. A whole genome sequencing is a complete genetic mapping of the human genome.

Analyses of two children
Department of Clinical Genetics and Department of Molecular Medicine have made a whole genome sequencing of two children to diagnose a possible rare disease.

Both children have developmental delay and dysmorphic features. Thus, a rare genetic disease was suspected. Using blood samples from the two children, their whole genome has been sequenced - in particular the 20,000 genes already mapped.

- The analyses did not reveal a genetic cause of the children’s developmental delay. But we have taken a big step forward being able to analyse the whole genome, says Jenny Friis, molecular biologist at Department of Clinical Genetics.

Children with rare diseases come first
According to the national strategy for personalised medicine, children and adolescents below the age of 18 years with a suspected rare disease are the first to be offered a whole genome sequencing.

- We believe that we will be able to establish a diagnosis in 25% of the cases. Moreover, the large amounts of data from the whole genome sequencing will be stored, enabling us to make a new analysis in a few years when we hopefully know more genetic variants causing specific diseases, says Sara Markholt, MD at Department of Clinical Genetics.

Today, we only understand the genetic coding in 2% of the genome; we lack knowledge of the remaining 98%. The development in this field is fast both in Denmark and internationally. This gives well-founded hope to learn more about genetic coding.

60,000 analyses in three years
The goal of the Danish National Genome Center is to complete 60,000 analyses nationally within the next three years. Of these, 1,000 analyses annually will be completed in children and adolescents below the age of 18 years with a suspected rare disease.

The Danish National Genome Center has two laboratory facilities. At Aarhus University Hospital in the western part of Denmark and at Rigshospitalet in Copenhagen. Interpretation of data takes place in all of the five Danish regions, but the capacity to interpret the large amount of analyses has not been established yet.

- We lack both doctors and molecular biologists to complete such a large number of analyses and the interdisciplinary capacity building is very important for our analysis work, says Jenny Friis.

FACTS on whole genome analysis:

• A whole genome sequencing is a complete genetic mapping of the 3 billion base pairs
• A whole genome sequencing can identifie any mutations in the genome. This can be used to establish a diagnosis and initiate adequate treatment
• Data on all genes in just one patient amount to 400 GB – equivalent to a pile of paper the size of the Round Tower in Copenhagen (approx. 42 m)

Read more about the Danish National Genome Center at https://eng.ngc.dk/

Further information:

Anders Bojesen, Administrative Consultant, Department of Clinical Genetics, Aarhus University Hospital, Tel.: +45 5380 9391, e-mail: andboj@rm.dk

Ole Halfdan Larsen, Administrative Consultant, Department of Molecular Medicine, Aarhus University Hospital, Tel.: +45 7845 5300, e-mail: ollars@rm.dk