Juvenile pernicious anaemia.

The extreme rarity of pernicious anaemia in childhood has been stressed by Lambert, Prankerd, and Smellie (1961) who, by insisting on positive evidence of intrinsic factor deficiency for the diagnosis, could accept unequivocally only 7 cases in the literature but added 2 of their own, who were sibs. They may have overlooked the case described by Wilkins (1957) which was later confirmed by McIntyre, Hahn, Conley, and Glass (1959). Since then, Leikin (1960) and Waters and Murphy (1963) have each reported 2 cases, also in sibs, while Morse, Cochrane, and Landrigan (1961), Clement, Nichol, and Welch (1961), Hung, Migeon, and Parrott (1963), and Pearson, Vinson, and Smith (1964) have added one each making the total 18. However, the cases of Reisner and Ellsworth (1955), Wilkins (1957), Morse et al. (1961), and Hung et al. (1963) were complicated by idiopathic hypoparathyroidism which usually preceded pernicious anaemia by 5 to 7 years. Since hypocalcaemia is thought to depress gastric function (Donegan and Spiro, 1960) and possibly also the secretion of intrinsic factor (Waters and Murphy, 1963), cases following endocrine disorders should be treated with reserve when conclusions are drawn regarding the nature of juvenile pernicious anaemia. A condition which is very similar clinically and which must be distinguished from juvenile pernicious anaemia is a chronic relapsing megaloblastic anaemia in children whose intrinsic factor activity is normal and who show no evidence of malabsorption. Imerslund (1960) described 10 such cases in 6 families. All showed a low serum vitamin B12 level but had a normal vitamin B12-binding factor in their gastric juice. In addition, persistent proteinuria and urinary tract abnormalities were common. Imerslund concluded that the megaloblastic anaemia was part of a hereditary syndrome due to selective malabsorption of vitamin B12 without intrinsic factor deficiency. Her 10 cases were later reinvestigated by Imerslund and Bjornstad (1963), using the Schilling test, and they found that in all of them there was a very low urinary excretion of B12 which did not increase when intrinsic factor concentrate