Article: Resequencing to Fine Map Known Idiopathic Pulmonary Fibrosis Risk Genes

July 2019
DNA is the instructions that make us who we are. Recent genetic studies have found there are regions of the DNA that are different in people with idiopathic pulmonary fibrosis (IPF) compared to the DNA of people without IPF.

Human DNA is large, being formed of a long chain of 3 billion chemical base pairs. This means that reading a person’s DNA is difficult and expensive. Therefore a technology called genotyping is commonly used in genetic studies.

Genotyping measures only a subset of the base pairs (usually between half a million and a million). Then we can estimate what the rest of that person’s DNA is likely to be as we know how DNA is inherited from our parents. This approach is much cheaper than reading the whole DNA and performs well for genetic mutations that are commonly found in the general population. Another approach, called sequencing, reads every single base pair of the DNA. Sequencing is more accurate than genotyping,but sequencing the entire DNA of participants in these genetic studies would cost millions of pounds.

A recent study, led by the University of Colorado, performed targeted sequencing on the DNA of individuals with and without IPF. In other words, they performed sequencing on the DNA, but rather than sequencing the whole 3 billion base pairs, they focussed on the regions of the DNA that have been previously reported as associated with IPF risk. By doing this, they were able to examine the IPF risk regions more closely than ever before and improve our understanding as to which specific genetic mutations are likely to be driving disease risk. Importantly, this study also confirmed that the regions previously identified using genotyping were genuinely associated with IPF risk. Better understanding these regions can help us work out which biological pathways are most likely to cause IPF and which pathways we may need to target if we want to develop a treatment to stop IPF.

APF trustee Professor Gisli Jenkins (University of Nottingham) and APF Mike Bray Research Fellow Dr Phil Molyneaux (Imperial College London) were involved in this study and aided in the collection of DNA samples from individuals with IPF.

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