[Selective vitamin B12 absorption disorder (Imerslund-Gräsbeck syndrome)].

The authors present a case of Imerslund-Gräsbeck syndrome, i. e. a familial megaloblastic anemia with proteinuria. The disease is due to congenital, selective malabsorption of vitamin B12. The subnormal absorption of vitamin B12 is not altered by orally given intrinsic factor, but parenteral vitamin B12 therapy results in complete recovery. Approximately 150 cases have been described in literature, the authors' case is the first in Hungary.