The prognosis in idiopathic hypercalcaemia of infants.

Two distinct types of idiopathic hypercalcaemia of infants have been recognized; a mild or simple type, in which recovery is said to be complete, and a severe type, which results in death or physical and mental retardation (Lightwood and Stapleton, 1953; Lowe, Henderson, Park and McGreal, 1954). Although most cases conform to one or other type, it has recently become apparent that the distinction is not a clear one, and that cases with features of both types may occur (Russell and Young, 1954; Rhaneyand Mitchell, 1956; Josephand Parrott. 1958). Moreover, a few of the supposedly mild cases have died and autopsy has disclosed nephrocalcinosis, affecting mainly the medulla of the kidney (Rhaney and Mitchell, 1956). Hence it is of some importance to determine whether infants with the simple type who recover clinically sustainanypermanent renal damage. The severe form of idiopathic hypercalcaemia is accompanied by considerable dwarfing (Schlesinger, Butler and Black, 1956; Fellers and Schwartz, 1958), while infants with the simple type show retardation of growth during the acute phase of the illness and often for some time thereafter (Creery and Neill, 1954). It is therefore of interest to know how long this retardation persists after the biochemical disturbance has been corrected. No full follow-up study has yet been reported although Forfar, Balf, Maxwell and Tompsett (1956) gave some details of four cases followed for one to three years; Creery and Neill (1954) briefly described the progress of their patients up to 18 months after the illness, and there have been reports on single cases (Bonham Carter, Dent, Fowler and Harper, 1955; Smith, Blizzard and Harrison, 1959). With a view to obtaining more detailed information about the prognosis, the progress of all children with the simple type of idiopathic hypercalcaemia seen in Dundee during a period of four years has been followed.