Three members from one family add support to a possible genetic basis for urticaria pigmentosa. A search of the world literature disclosed 28 additional individuals with various forms of urticaria pigmentosa among their relations. These came from 13 different families. The pedigrees of the 31 patients suggest an autosomal dominant mode of transmission.
Shaw JM. Genetic Aspects of Urticaria Pigmentosa. Arch Dermatol. 1968;97(2):137-138. doi:10.1001/archderm.1968.01610080041006