Review paper
The role of filaggrin gene mutations in pathogenesis of atopic dermatitis. Literature review

Atopic dermatitis (AD) is a common, chronic and relapsing skin disease of complex aetiology, with interactions between susceptibility genes and environmental factors. An impaired epidermal barrier resulting in increased water loss and reduced hydration of the skin is a prominent part of the AD clinical picture. Though primary epidermal barrier defect was taken into account as a possible causative factor for AD, in the last decades most genetic studies on pathogenesis of atopic diseases have focused on immunological mechanisms. Filaggrin, a major component of keratohyalin granules in the granular layer, is a protein which function is to aggregate filaments of keratin, resulting in formation of the corneocyte’s cornified envelope. The cornified cell envelope prevents not only water loss but also entry of allergens and subsequent allergic sensitization, which may result in atopy development. Recent studies revealed that null mutations in filaggrin genes that cause ichthyosis vulgaris are strong predisposing factors for atopic dermatitis and asthma. The first study on the role of filaggrin mutations in AD was successfully replicated in the other populations.