Thick skinned

Lipoid proteinosis — also known as hyalinosis cutis et mucosae or Urbach–Wiethe disease — is a rare, autosomal recessive disorder of unknown cause, characterized by a generalized thickening of skin, mucosae and certain viscera. In April Human Molecular Genetics, Takahiro Hamada and colleagues from The Guy's, King's College and St Thomas' Hospitals' Medical School, London, UK, show that lipoid proteinosis maps to 1q21 and is caused by mutations in the extracellular matrix protein 1 gene (ECM1).

Hamada et al. performed genome-wide linkage on DNA from three affected siblings in a consanguineous Saudi Arabian family and observed that the disorder maps to 1q21. Further DNA analysis from 28 affected individuals from five other unrelated consanguineous family groups from different geographical regions also showed complete linkage. In addition, by comparing control versus LP gene expression in cultured fibroblasts they identified six different homozygous loss-of-function mutations in ECM1 (...