Sjogren: unique surname, two men, four syndromes and one disease.

Henrik and Torsten Sjogren (/'ʃoʊgrən/ or SHOH-grən) were two Swedish physicians living in the same period, but completely unrelated, except for their notable contributions to Medicine. The first one described keratoconjunctivitis sicca, afterward called Sjogren's syndrome, and a fishing net aspect retinal pigmentation affecting visual acuity, nowadays known as Sjogren reticular dystrophy. The last one contributed to the understanding of Spielmeyer-Sjogren disease, Marinesco-Sjogren, and Sjogren-Larsson syndromes, all related to genetic disorders and neurological symptoms. In this paper, we aim to describe each disorder, in order to avoid any misunderstanding in diagnosis and for historical record.