Protein intake can not be estimated from urinary urea excretion.

We assessed the relationship between protein intake (calculated from a 3-day prospective dietary diary) and 24-h urinary urea excretion in 37 children with chronic renal failure. Protein intake was not restricted during the investigation period. The 24-h urinary urea excretion correlated poorly with the protein intake estimated from the dietary diary (r = 0.58). We conclude that although it is common practice to assess compliance with a protein-restricted diet in children with chronic renal failure with a dietary diary and 24-h urinary urea excretion, the value of this assessment is questionable.

Idiopathic arterial calcification of infancy.

We describe two twin sisters in whom calcification of different arteries was detected in the first weeks of life. Transient renal insufficiency, arterial hypertension, and skeletal abnormalities were also observed. One child had anasarca and heart decompensation at birth. Prenatal infarction of one kidney had occurred in the same infant. A kidney biopsy showed calcium deposits in all the layers of the arteries. Most findings in these patients are compatible with idiopathic arterial calcification of infancy (IACI). Investigation of calcium and phosphorus metabolism revealed spontaneously receding hypercalciuria, increased intraerythrocytic calcium levels, and transient X-ray abnormalities of the long bones. Treatment initially consisted of biphosphonate and later, the calcium antagonist flunarizin. A progressive diminution of the arterial calcification was observed in the course of both treatments.

Recurrent haemolytic uraemic syndrome and acquired hypomorphic variant of the third component of complement.

In a girl with recurrent haemolytic uraemic syndrome (HUS), persistently low serum levels of C3 were found. Analysis of complement phenotype revealed a hypomorphic variant of C3 Fast in the patient (C3fS) and a normal heterozygous pattern in both parents and the brother (C3FS). Other complement aberrations in the patient were: the presence of a null gene for C4A and C4B and low serum levels of factor H. The father also had partial factor H deficiency. It is hypothesized that the hypomorphic C3 variant may predispose to recurrent HUS. In the acquired forms the role of uraemia in alteration of C3F should be considered.

Lacrimo-auriculo-dento-digital (LADD) syndrome with renal and foot anomalies.

A patient who presented with most features of lacrimo-auriculo-dento-digital (LADD) syndrome, an autosomal dominant trait, is described. There was no deafness, and anomalies of the external ear and the upper limbs were discrete. Renal anomalies, consisting of progressive caliectasis with stone formation, were revealed by macroscopic hematuria. There were also skeletal anomalies of both feet, a feature not previously described. Renal and distal limb anomalies are probably features of LADD syndrome.

Hypophosphatemia in infants on continuous ambulatory peritoneal dialysis.

Three infants with irreversible renal failure and treated with continuous ambulatory peritoneal dialysis (CAPD) developed hypophosphatemia. In one of them rachitic lesions were observed on X-ray and bone biopsy showed osteomalacic osteodystrophy. Different mechanisms may have been at the origin of the hypophosphatemia: high doses of phosphate binders, low phosphorus intake, phosphate loss with the dialysate and possibly nutritional repletion. Dietary phosphorus restriction and use of phosphate binders should be applied with caution and serum phosphate should be monitored regularly in infants treated with CAPD.

Symmetrical necrosis of the basal ganglia in methylmalonic acidaemia.

In a patient with methylmalonic acidaemia (MMAA), persistent neurological symptoms were observed in addition to the acute episodes of metabolic dysequilibrium. CT scan and magnetic resonance imaging revealed bilateral symmetrical necrosis of the globus pallidus. Different episodes of metabolic decompensation, one with severe acidosis, had occurred. Persistent neurological symptoms in patients with MMAA who are appropriately treated suggest irreversible brain damage which appears to occur preferentially at the level of the basal ganglia.

Acute sodium valproate intoxication: occurrence of renal failure and treatment with haemoperfusion-haemodialysis.

In a child who probably received an overdose of sodium valproate, progressive coma, intermittent tonic-clonic seizures and anuria developed. Laboratory investigations revealed coagulopathy, and anaemia and mildly disturbed liver function. Progressive renal insufficiency, probably due to rhabdomyolysis and myoglobulinuria, occurred later. Treatment consisted of supportive measures, combined haemoperfusion and haemodialysis and IV thiopentone. Clinical and biochemical normalisation was observed after 11 days.

Bronchogenic cysts in children.

Three children with symptomatic bronchogenic cysts are presented. Because of the variability in clinical presentation and the shortcomings of diagnostic procedures, bronchogenic cysts present a diagnostical problem. In view of the risk of serious complications an aggressive attitude towards all congenital cystic lung lesions is advised, even when they are asymptomatic. Surgical excision assures an excellent outcome in most cases, and is therefore the treatment of choice.

Marshall-Smith syndrome: new aspects.

A 4-year-old girl with the Marshall-Smith syndrome (MSS) is described. A muscle biopsy was performed because of hypotonia and muscular weakness. Selective hypoplasia of type IIa and IIb fibers was found. Additional not previously reported findings in this girl were a partial growth hormone deficiency, a partial villous atrophy of the small bowel and a pronounced dicarboxylic aciduria. The significance of these findings in MSS is not clear and the results of similar investigations in other MSS patients have to be awaited.

Defect in succinate oxidation by isolated muscle mitochondria in a patient with symmetrical lesions in the basal ganglia.

A 3-year-old boy was referred for evaluation of psychomotor retardation. He had a waddling gait with proximal hypotonia and paresis. Computed tomography (CT scan) and magnetic resonance imaging (MRI) of the brain demonstrated symmetrical lesions in the basal ganglia suggesting bilateral necrosis. Lactate and pyruvate levels in blood and cerebrospinal fluid were persistently elevated. A biopsy of the quadriceps muscle showed normal light microscopic findings except for a slightly raised number of lipid droplets. Electron microscopy confirmed this and also showed a rather large number of subsarcolemmal mitochondria without crystalline inclusions. Biochemical studies showed a normal carnitine level and normal mitochondrial enzyme activities in muscle homogenate, including succinate-cytochrome c reductase. However, intact isolated mitochondria failed to oxidize succinate. An explanation for this paradoxical finding is a deficiency in that part of the coenzyme Q (CoQ) that is reduced by the succinate dehydrogenase complex. The differential diagnosis between Leigh's syndrome and infantile bilateral striatal necrosis (IBSN) is discussed. The role of neuroradiology in prompting complementary investigations is stressed.

Aluminum accumulation in children on chronic dialysis: predictive value of serum aluminum levels and desferrioxamine infusion test.

In 7 children on chronic dialysis the correlation between serum aluminum, aluminum after desferrioxamine (DFO) challenge and bone aluminum was studied. In children the DFO challenge test is not superior to the serum aluminum level for the estimation of aluminum body burden. A significant correlation between serum aluminum and bone aluminum content was found. In all children, except one, aluminum bone content was markedly elevated.

Idiopathic cerebral arterial infarction with paucity of symptoms in the full-term neonate.

Two full-term neonates, one with convulsions and intermittent generalized hypotonia and one with poor sucking, temperature instability, and lethargy, are reported. CT scan findings suggested cerebral arterial infarction. Arteriography revealed occlusion of the middle cerebral artery, unilaterally in the first and bilaterally in the second patient. The evolution of the infarct could be followed on serial CT scans. No predisposing factors during pregnancy or delivery were found, and serious neurologic deficits developed in both children. These cases demonstrate that, even in full-term neonates with discrete or moderate neurologic symptoms and born after normal pregnancy and delivery, the possibility of vasoocclusive brain infarction should be considered. The diagnosis is suggested by imaging techniques, of which CT scanning seems to have the greatest value at present. This technique also permits the follow-up of the lesions. The prognosis for neurologic development appears to be variable: minor neurologic deficits as well as unexplained spastic hemiplegia in older children may be the consequence of inapparent cerebral arterial infarction in the neonatal period.

Abdominal colic due to ureteric diverticulum with stone formation.

In a 15-year-old boy right lower abdominal colicky pain was caused by intermittent obstruction of the ureter by stones which had accumulated in a ureteric diverticulum. As was shown by repeated X-rays, each of these stones had moved to the ureter and back to the diverticulum. Ureteric diverticulum mostly remains asymptomatic in children: stone formation and obstruction of the ureter by the stones is one of the instances which may cause symptoms.

Benign mitochondrial myopathy with deficiency of NADH-CoQ reductase and cytochrome c oxidase.

Since birth a female child had been weak and hypotonic. At three months of age, head control was lacking; sucking and crying were poor. Four months later, there were more spontaneous movements and the girl was able to push herself up in prone position. Further motor improvement was noted at the age of 15 months. A 25-year-old brother of the patient's mother was very floppy during early childhood and has still some difficulties to swallow. Laboratory work-up showed elevated blood lactate and pyruvate levels, a mild hyperalaninemia and hyperalaninuria and an increased urinary excretion of dicarboxylic acids. Light and electron microscopy of a muscle biopsy disclosed a mitochondria-lipid-glycogen myopathy. Biochemical studies on a second muscle specimen revealed a combined deficiency of NADH-CoQ reductase and cytochrome c oxidase with a low carnitine level. There exists a considerable clinical and biochemical heterogeneity among the myopathies due to disturbances in the mitochondrial respiratory chain.

Haemorrhagic shock and encephalopathy.

Two infants are described with a fulminant disorder characterised by profound circulatory collaps and shock, generalised convulsions and unremitting coma, bleeding due to severe DIC, fever, diarrhoea, metabolic acidosis and renal and hepatic failure. Both infants died shortly after onset of the symptoms. Autopsy mainly revealed haemorrhages in different organs, anoxaemic lesions in the brain and a normal structure of liver and pancreas. No causative agent could be demonstrated. We believe that both patients suffered from haemorrhagic shock and encephalopathy, a mostly fatal disorder which has recently been described. Although the clinical and biochemical features are very distinctive, this syndrome is probably heterogeneous and its differentiation from some other disorders may be difficult. Its pathogenesis is unknown but there are some indications that intravascular activity of trypsin may play a role. During a study of the two families we obtained abnormal results of immunologic tests in most members: the interpretation of this finding remains conjectural. Haemorrhagic shock and encephalopathy may occur more frequently than the restricted literature on this subject suggests. Future studies will have to deal with the question of identity and pathogenesis.

Monozygotic twins non-concordant for oligomeganephronic renal hypoplasia: artery-vein placental shunting as a possible pathogenetic mechanism.

The etiology and pathogenesis of oligomeganephronic renal hypoplasia (OMN) are not known. In the present paper a second case of monozygotic twins non-concordant for OMN is described. It is hypothesized that one of the mechanisms which have been proposed to explain structural defects in monozygotic twins, namely placental artery-vein shunting, may have been involved in the pathogenesis of OMN in these patients. In OMN in general vascular abnormalities may have to be considered as a pathogenetic mechanism.

Benign ureteral fibrous polyp as a cause of obstruction in children.

In an 11-year-old boy with intermittent colicky flank pain for several years unilateral obstruction caused by benign ureteral fibrous polyps was found. The radiologic characteristics are discussed and the need for conservative surgery is stressed.

Familial erythrophagocytic lymphohistiocytosis.

A patient is described in whom the clinical symptoms and the laboratory data suggested familial erythrophagocytic lymphohistiocytosis (FEL). This diagnosis was confirmed by the findings on liver biopsy. The literature on FEL, a fatal disease with probable autosomal recessive inheritance, is reviewed. Some recently described aspects of FEL, such as hyperlipidemia and disturbances of the immune system, are stressed: the latter may play a role in the pathogenesis of the disease.

Familial nature of congenital absence and severe dysgenesis of both kidneys.

Seventy-one parents and 40 siblings of 41 index patients with bilateral renal agenesis, bilateral severe dysgenesis, or agenesis of one kidney and dysgenesis of the other were evaluated by gray-scale ultrasonography for genitourinary malformations. Nine per cent (10 of 111) had asymptomatic renal malformations, most often unilateral renal agenesis (4.5 per cent--a frequency that was significantly higher than the frequency of 0.3 per cent among 682 adults [P less than 0.004]). We recommend ultrasonographic screening for parents and siblings of infants born with agenesis or dysgenesis of both kidneys or with agenesis of one kidney and dysgenesis of the other, since renal malformations may have medical implications even for asymptomatic patients.