H Luthman — Page 6 | PubMed Health

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The Wiskott-Aldrich syndrome gene as a candidate gene for atopic dermatitis.

Atopic dermatitis is a multifactorial disorder probably caused by environmental factors in combination with susceptibility genes. The clinical similarity between atopic dermatitis and the eczema manifestation in patients with Wiskott-Aldrich syndrome made the previously identified WAS gene in chromosome sub-band Xpl 1.23 an interesting candidate gene for atopic dermatitis. We studied linkage and association to the WAS gene region using four polymorphic microsatellite markers in 406 Swedish families with at least two siblings affected with atopic dermatitis (in total 1514 individuals). In the analyses, we studied two qualitative traits: atopic dermatitis and elevated allergen-specific serum IgE antibodies, and one quantitative trait, a severity score of atopic dermatitis. We found that the marker MAOB gave positive linkage with a maximum lod score of 1.68 (p<0.05) to the severity score of atopic dermatitis. Association could not be seen to atopic dermatitis nor to elevated allergen-specific serum IgE antibodies in this region using the transmission disequilibrium test. Our results indicate that either the WAS gene or another gene in the area contributes to the severity of atopic dermatitis.

Age of Onset↗

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Characterization by phenotype of families with atopic dermatitis.

The aetiology of atopic dermatitis is unknown, but is probably multifactorial, with interactions between several genetic and environmental factors. Twin studies indicate a strong genetic factor, but the susceptibility genes are unknown. This paper, describing the phenotypes of family material, forms part of a large genetic study seeking to identify susceptibility genes for atopic dermatitis by linkage analysis. We selected families with at least 2 siblings affected with atopic dermatitis (1,097 affected siblings who together form 650 affected sib pairs and 49 affected half-sib pairs). We established a phenotype database of information about the affected siblings and their relatives, in total 5,830 individuals. All siblings were diagnosed with atopic dermatitis and participated in a standardized interview covering aspects of atopy and atopic dermatitis. Of the affected siblings, 72% suffered or had suffered from asthma and/or allergic rhinoconjunctivitis and 74% had raised total and/or allergen-specific IgE serum levels. Seventeen percent of the siblings had been hospitalized for atopic dermatitis. Sixty-nine percent had 1 or both parents with atopic dermatitis. Among siblings with 1 parent with atopic dermatitis, 37% had a father with atopic dermatitis and 63% had a mother with atopic dermatitis, indicating maternal preponderance. Analysis of the occurrence of atopic dermatitis in relation to the birth order in the sibship shows an increased risk of atopic dermatitis in persons born early in a sibship. Although the families were selected for genetic sib-pair linkage analysis, we believe that this material is representative of atopic dermatitis families managed at hospitals in Stockholm.

Adolescent↗