A new c.1845A→T of oncostatin M receptor-β mutation and slightly enhanced oncostatin M receptor-β expression in a Chinese family with primary localized cutaneous amyloidosis.

Primary localized cutaneous amyloidosis (PLCA) is a chronic itching skin disease with amyloid material deposited in the upper dermis. PLCA is more common in Southeast Asia and South America, where up to 10% of cases may be familial. Mutations of OSMR or IL31RA have been identified in PLCA. Here we detected a new OSMR mutation in a lichenoid PLCA family from north China. This is the first report of PLCA with gene mutation on the Chinese mainland. A heterozygous 1845A→T was found in exon 13 of the proband, causing p.Lys615Asn substitution, which was not found in screening 100 ethnically matched healthy controls. The particular mutated amino acid is well conserved throughout various evolutionary lineages, located within the second fibronectin III-like domain of oncostatin M receptor β subunit (OSMRβ), and in close vicinity to a previously reported mutation, p.Gly618Ala. Immunohistochemistry showed slightly enhanced OSMRβ expression in the lesion of the proband. This study extends the knowledge of PLCA gene mutation and further supports the pathogenic role of OSMRβ in PLCA.