Isolated sulfite oxidase deficiency.

Isolated sulfite oxidase (SO) deficiency is an autosomal recessively inherited inborn error of sulfur metabolism. In this report of a ninth patient the clinical history, laboratory results, neuropathological findings and a mutation in the sulfite oxidase gene are described. The data from this patient and previously published patients with isolated sulfite oxidase deficiency and molybdenum cofactor deficiency are summarized to characterize this rare disorder. The patient presented neonatally with intractable seizures and did not progress developmentally beyond the neonatal stage. Dislocated lenses were apparent at 2 months. There was increased urine excretion of sulfite and S-sulfocysteine and a decreased concentration of plasma cystine. A lactic acidemia was present for 6 months. Liver sulfite oxidase activity was not detectable but xanthine dehydrogenase activity was normal. The boy died of respiratory failure at 32 months. Neuropathological findings of cortical necrosis and extensive cavitating leukoencephalopathy were reminiscent of those seen in severe perinatal asphyxia suggesting an etiology of energy deficiency. A point mutation that resulted in a truncated protein missing the molybdenum-binding site has been identified.

Focal segmental glomerulosclerosis with idiopathic nephrotic syndrome: three types of clinical response.

In a retrospective analysis, 51 patients with focal segmental glomerulosclerosis and idiopathic nephrotic syndrome, who were treated with steroid or cyclophosphamide therapy, were divided into three clinical groups according to the remission profile of their nephrotic syndrome. Group 1 patients (19.37%) consistently responded to medication; none has progressive renal failure (mean follow-up 10.6 years). Group 2 patients (25, 40%) failed to respond to medication; terminal renal failure has occurred in 12 of them. Group 3 patients (7, 14%) initially appeared to be responsive to medication and continued to respond for up to 18 months, but subsequently became unresponsive to any therapy; five of them have required dialysis or transplantation. This third group of patients could not be separated clinically or pathologically from group 1 patients, all of whom have an excellent prognosis. One should, therefore, be cautious about predicting the outcome of steroid-responsive nephrotic patients, especially those with FSGS, until at least 18 months after the onset of illness.

Acute renal failure of short duration in minimal lesion nephrotic syndrome of childhood.

Two boys 12 and 8 years of age with biopsy proven minimal lesion nephrotic syndrome developed acute renal failure during the course of their illness. Renal failure developed in the first boy at the time of onset of his nephrotic syndrome while in the second boy it occurred at the time of a relapse of his disease, 5 1/2 years after onset. Both patients had a complete resolution of renal failure and nephrosis following peritoneal dialysis and oral prednisone. Acute renal failure requiring dialysis is an unexplained and rare complication of minimal lesion nephrotic syndrome in adults and children.

Method for predicting when children with progressive renal disease may reach high serum creatinine levels.

Optimal planning of therapy for children with progressive renal failure requires accurate prediction of the age at which the serum creatinine (SC) level of the patient will be sufficiently high to warrant dialysis or renal transplantation. In a retrospective study of 29 children with progressive renal disease, linear regressions for each child were developed from the reciprocal of serum creatinine (1/SC) on time. It was found that in children, as in adults, the rate of deterioration of renal function expressed as 1/SC described a linear regression. From the regressions developed, it was determined that predictions using at least six 1/SC values on time would have given acceptable estimates of the age at which dialysis treatment became necessary. With the more precise measurement of SC now available it is likely that even more accurate predictions will be possible in the future.