Wanted: 5,000 healthy S'poreans

NHCS study seeks to find what's the norm for locals

RESEARCHERS at the National Heart Centre Singapore (NHCS) are working hard to establish what "normal" looks like in Singapore.

The centre's biobank is looking to recruit 5,000 healthy volunteers to donate blood samples, which will be used as a reference set to help understand the genetic make-up of the average healthy Singaporean.

"We want to understand what is normal in the local population, so that we can really start to deal with what is abnormal," said Professor Stuart Cook, director of the National Heart Research Institute Singapore.

"It'll be the bedrock for our comparison. Most of the people we see are sick, so we haven't studied the normal people," added Prof Cook, who is also a Tanoto Foundation professor in cardiovascular medicine at SingHealth Duke-NUS Academic Medical Centre.

Existing databases, he said, focus on foreign populations with a Caucasian majority and do not account for ethnic and other differences. What is considered "abnormal" based on overseas studies may be "normal" here, and vice-versa, he added.

A reference of what is normal for Singaporeans will help researchers to look at diseases that locals are genetically predisposed to and, thus, at higher risk of developing.

"We look for mutations in genes," said Prof Cook. "We might find that... in 300 of those 5,000, there's a certain mutation that predicts those people go on to get cancer."

It will also mean that healthy people who have already been flagged as having abnormal health parameters may no longer have go for repeated follow-up visits.

Prof Cook gave the example of 18-year-olds serving National Service, who tend to have larger hearts than usual. "They're very fit, so their hearts are quite big and, therefore, you might call this abnormal," he said. "Actually, they're probably normal. But we don't know what is normal for an 18-year-old male who is active."

More than 800 healthy volunteers have been recruited and the team is hoping to recruit the remainder over the next five years.

Apart from blood samples, volunteers will need to answer a detailed questionnaire about their lifestyle, undergo an magnetic resonance imaging (MRI) scan, and have their blood pressure, body fat and heart rate measured.

The process takes about two hours and donated samples can be kept for decades.

As a start, the centre will be looking at genes that increase one's risk of sudden death, high cholesterol and thickening of the heart.

Two tissue repositories - set up by SingHealth and the National University Health System - serve a similar purpose as the NHCS biobank. However, they generally focus on collecting and investigating diseased rather than healthy tissue.

Those who wish to contribute to the NHCS biobank can call 9159-7029 during office hours or e-mail biobanking_enquiries@nhcs.com.sg.

linettel@sph.com.sg

A version of this article appeared in the print edition of The Straits Times on June 29, 2015, with the headline 'Wanted: 5,000 healthy S'poreans'. Print Edition | Subscribe