University of Dundee

Major American award for Dundee skin expert

08 May 2009

Professor Irwin McLean, of the University of Dundee, has been awarded the American Skin Association Achievement Award for his pioneering work on skin diseases.

Professor McLean, who discovered that mutations on the filaggrin gene cause eczema and other related disorders, was presented with the award at the Society for Investigative Dermatology Annual Meeting in Montreal.

'I am delighted to receive this prestigious honour from our American colleagues in recognition of our work on the filaggrin gene in eczema as well as our previous work on other inherited skin diseases,' said Professor McLean, who is based in the Division of Molecular Medicine at Dundee.

'I am enormously grateful to past and present members of my research group, our many collaborators and many patients and families both locally and worldwide, without whom none of this would have been possible.'

The award cites Professor McLean’s work in the area of autoimmune and inflammatory skin disorders.

Prof McLean is a human geneticist and skin biologist based at Dundee. He is the leading expert in the biology and genetics of the filaggrin gene and discovered its importance in human skin disease and allergy.

Normal people have two functional copies of the filaggrin gene (one copy inherited from each parent).

The McLean laboratory previously showed that >10% of the population carry genetic mutations that completely 'knock out' the function of one of their filaggrin genes (Smith et al., Nature Genetics 38: 337-342, 2006). These people have skin that is drier than normal and may have mild scaling or flaking of the skin (mild ichthyosis vulgaris). About 1 in 90 of the UK population carry two filaggrin mutations and their skin completely lacks this protein. They have severely dry and flaky skin (severe ichthyosis vulgaris).

The McLean group went on to show that these same mutations are a major genetic predisposing factor for eczema (also known as atopic dermatitis) and other related allergic conditions, importantly including a form of asthma secondary to eczema (Palmer et al., Nature Genetics 38: 441-446, 2006).

The McLean laboratory subsequently showed that white European populations carry at least 5 common filaggrin mutations as well as many other rare mutations, all of which 'knock out' the production of filaggrin protein in the skin and are important in genetic predisposition to eczema and related allergic diseases (Sandilands et al., Nature Genetics 39: 650-654, 2007).

In their most recent published research, Professor McLean team, together with colleagues in Ireland, showed that mice carry a genetic defect that leads to allergic inflammation, comparable to that seen in human eczema and related allergic diseases.

The work further confirmed the role of the filaggrin gene in building up the barrier layers of the skin, demonstrating how mutations in this gene lead to conditions such as eczema.

Filaggrin is an abundant protein in the outermost layers of the skin and is produced by the filaggrin gene. Filaggrin’s function is to help produce the impermeable skin barrier layers present at the skin’s outermost surface and to keep these hydrated.

The skin’s inherent barrier function is akin to plastic or cling film - it acts to prevent water loss from the skin and importantly, to protect the body from foreign materials in the environment, such as allergens.

Lack of an intact skin barrier leads to allergens entering the body where they produce a range of allergic responses that include eczema, asthma, hay fever and other allergies.