DETAILED CLINICAL AND BIOCHEMICAL REPORT ON TWO BROTHERS SUFFERING FROM LIGNAC‐FANCONI DISEASE: (Cases 10 and 11 in this series)

Summary The case records of two brothers suffering from Lignac‐Fanconi disease are given in detail. Two further siblings probably suffered from the disease. The results of certain special investigations are discussed. In a mineral balance we have not been able to prove that the hypophosphataemia in one of the cases was due to an excessive excretion of phosphorus. In both brothers the glutamic acid level in the serum was found to be raised. This supports the view that a disorder of aminoacid metabolism is the underlying cause of the disease. It is suggested that the large quantity of aminoacids passed by the kidneys has a nephrotoxic action. The pathogenesis of other features of the disease can be explained by dysfunction of tubular reabsorption caused by this action, and the ultimate onset of renal failure can be explained by the same action involving the glomeruli. With alkali therapy the general condition of both boys has improved, although a normal plasma CO2 combining power could not be reached in either case. High vitamin D dosage has produced some healing of the skeletal changes, but attention is drawn to the possibly dangerous effects of this treatment. One case died from heart failure secondary to renal failure after three months treatment. The genetics of the disease are discussed. The evidence presented from our cases seems to confirm the theory of a recessive inheritance.