“We can give hope to these patients”

The heel-prick test is a rite of passage for new-borns and their nervous parents, who stand by wishing they could endure the pain instead of their new arrival.

However, in the not-too-distant future this milestone could be replaced with the sequencing of a baby’s entire genome.

Moorfields Eye Hospital consultant ophthalmologist, Mariya Moosajee, emphasised to delegates at 100% Optical the importance of patients with inherited retinal disease getting a genetic diagnosis.

“Patients need their genetic diagnosis because we are now potentially able to offer them treatments. We can give hope to patients where previously there was none,” she explained.

“These are exciting times,” Ms Moosajee added.

Optometrists should refer patients for a molecular diagnosis so they can access genetic counselling, family planning services and appropriate potential treatments.

Ms Moosajee shared that practitioners would often be asked by patients whether there was a treatment for their condition.

“They are sort of trying to run before they can walk…Referring your patients for genetic testing is step one,” she highlighted.

She highlighted that the genetic therapy, Luxturna, has been approved by the US Food and Drug Administration for the treatment of RPE65 mutation-associated retinal dystrophy.

The treatment is currently being considered by the National Institute for Health and Care Excellence for use in the UK.

While the cost of Luxturna is set at $850,000 (£597,000) for both eyes in the US at present, Ms Moosajee predicted that the cost of genetic therapy will reduce in the future.

“There are other therapies at different stages of development. Once these gene therapies start to get approval there will be competition in the market and these prices will go down,” she elaborated.

Ms Moosajee explained that 60% of blindness in infants worldwide is caused by genetic disorders, while inherited retinal disorders are the leading cause of certifiable blindness among working age adults in the UK.

Although many patients are told they have ‘retinitis pigmentosa’, this is a description of the disease not a diagnosis, Ms Moosajee emphasised.

“We need to know what gene is causing the disease so we can give patients an accurate treatment,” she added.

Through screening the coding regions of the genome, scientists have discovered 240 genes that are linked to eye disease.

However, a new approach that involves sequencing the whole genome holds enormous potential for screening known disease-causing genes and identifying new ones.

This process involves sequencing three billion bases, including 20,000 genes and non-coding regions.

“Currently in the UK we are having a revolution in the way that we undertake genetic testing,” Ms Moosajee highlighted.

The challenges of whole genome sequencing include that the file of data produced by a single individual is 600GB in size, and this needs to be stored safely over a patient’s lifetime.

Within each genome, there are four million changes that are unique to an individual.

“It’s like looking for a needle in a haystack when you are looking for genetic disease,” Ms Moosajee explained.

At present, Genomics England is undertaking the 100,000 Genomes project, which aims to sequence the genomes of 70,000 NHS patients and family members.

Half of the patients involved in the project have rare diseases, while half have cancer.

The project started in 2013 and is due to be completed at the end of September this year.

Ms Moosajee highlighted that the point of the 100,000 Genomes project is to integrate genomic medicine into NHS care.

She added that by 2020, the NHS plans to embed genetic medicine as part of routine care.

“When a child is born, instead of taking that heel prick test, they’ll sequence the whole genome,” she observed.