Thyroid hormones are essential for childhood development and adult health, and thyroid disease affects up to 10 per cent of people in the world - yet we are only now beginning to understand the genetic architecture of thyroid levels.
A new international study of thyroid hormone levels published this month in the leading journal Nature Communications. Its lead author is an Adjunct Associate Professor Scott G. Wilson from The University of Western Australia.
While synthetic thyroid hormones are among the most common drug therapies prescribed globally, the genetic control of these vital hormones is poorly understood.
However, thanks to detailed genetic data available through a whole genome sequencing study, the UK10K project, Professor Wilson and fellow researchers have identified rare variants associated with thyroid hormone levels which could not have been detected in earlier studies.
The project has discovered a new gene called SYN2 which appears to play an important role in the control of thyroid stimulating hormone.
The study brought together data from 16,000 people around the world including those in the Busselton Thyroid Study (part of the ground-breaking Busselton Population Health Study which was started in the 1960s), and in other big global population studies including TwinsUK, the UK-based Avon Longitudinal Study of Parents and Children, and major studies in Italy.
"The whole genome sequence data has enabled us to identify that both common genetic variants with modest effects and rarer genetic variants with larger effects determine a person's thyroid status," Professor Wilson said.
Clinical Professor John Walsh, who was also involved in the study, said: "This has implications for the diagnosis and treatment of hypothyroidism (thyroid underactivity). Some people may have borderline thyroid function tests because they have inherited rare genetic variants and not because of thyroid disease. In which case, they don't need to be treated with prescription medicines."
Adjunct Associate Professor Scott G. Wilson (UWA School of Medicine and Pharmacology) (+61 8) 9346 2089
Clinical Professor John Walsh, (UWA School of Medicine and Pharmacology) (+61 8) 9346 2466
David Stacey (UWA Media and Public Relations Manager) (+61 8) 6488 3229 / (+61 4) 32 637 716