Nephrocalcinosis and urolithiasis in carbonic anhydrase II deficiency syndrome

We report three new Kuwaiti patients with carbonic anhydrase II deficiency (CA II) from two unrelated families. Each patient had osteopetrosis, distal renal tubular acidosis, and cerebral calcification. Patients from family 1 (a brother and a sister) had some facial anomalies and delayed development. At the age of 14 months, ultrasound studies in the girl showed medullary nephrocalcinosis which has not been previously described in association with CA II, while cerebral CT scan revealed dilated ventricles. The patient from family 2, who had two previously reported affected siblings, developed bilateral recurrent renal stones and hypercalciuria but no nephrocalcinosis. None of his affected siblings had nephrocalcinosis or urolithiasis. DNA analysis of patients from both families showed that each of them was homozygous for the “Arabic” mutation in the CA II gene. We report new features in three Arab patients with CAII deficiency. Also review all previously reported CA II cases from Kuwait in order to highlight the inter-/intra-familial variability of the disease in this part of the world despite the overwhelming prevalence of the same “Arabic” mutation among the patient population. Received: 17 January 1997 / Accepted in revised form: 18 June 1997     

Nephrocalcinosis in children: a retrospective multi-centre study

Aim:  To review the data of children with NC and to analyse aetiology, clinical manifestations, growth and renal function at presentation; to relate growth and renal function to changes in NC in patients with a follow-up of at least 12 months.
Methods:  Data of 41 children from four institutions were gathered retrospectively.
Results:  Presenting symptoms were failure to thrive in the first year of life (41%), urinary tract infections, bladder voiding dysfunction or abdominal pain (17%) and psychomotor delay (10%). In 24% of cases NC was detected incidentally. Glomerular function at diagnosis was normal in 83% of children. During a median follow-up of 4 yrs and 5 months in 28 patients, growth standard deviation score improved from a median of −2.2 to −1.0 and glomerular function remained stable in 89% of patients, in spite of worsening of the degree of NC in 62% of cases. The most frequent causes of NC were hereditary tubulopathies and vitamin D intoxication.
Conclusion:  Our results show that the treatment of the underlying conditions is associated with catch-up growth and stabilization of glomerular function in many children, but not with the reduction in the degree of NC in the majority of cases. We believe that early recognition of conditions leading to NC is clinically useful and suggest a diagnostic flowchart, which may be helpful in the approach to NC.     

Renal Tubular Acidosis in a Case of Shwachman's Syndrome

ABSTRACT. We describe metabolic acidosis in a 15-month-old girl with clinical features of Shwachman's syndrome. Renal function tests indicated that the patient had type 1 renal tubular acidosis. Based on our findings and other reports of renal tubular dysfunction in patients with Shwachman's syndrome, we conclude that it is important to look for a possible renal tubular defect in this syndrome.     

Nephrocalcinosis in glucose-galactose malabsorption: nephrocalcinosis and proximal tubular dysfunction in a young infant with a novel mutation of SGLT1

We report an association of proximal renal tubular dysfunction in a 50-day-old girl with glucose-galactose malabsorption who was found to have nephrocalcinosis, but no sign of nephrolithiasis. A novel homozygous nonsense mutation at 267Arg →stop (CGA→TGA) in the Na⁺-dependent glucose transporter (SGLT1) was found in loop 5 connecting transmembrane segments 6 and 7, indicating the complete loss of glucose transport activity. This case indicates that hypercalcaemia, nephrocalcinosis and proximal tubular dysfunction may be seen in association with glucose-galactose malabsorption and that most of these abnormalities improve with a glucose-galactose-free diet.     

THE SYNDROME OF RENAL TUBULAR ACIDOSIS WITH NERVE DEAFNESS

Abstract. Two brothers with renal tubular acidosis and nerve deafness are described. Studies of the physiopathological characteristics of the renal acidification defect show that the defect is limited to the distal tubule. Renal tubular acidosis with nerve deafness is a distinct nosologie entity that is determined by an autosomal recessive trait.     

以肾小管酸中毒为首发表现的儿童恶性淋巴瘤

原发性肾淋巴瘤是原发于淋巴结以外的一种恶性淋巴瘤,罕见于儿童。该文报道2例以肾小管酸中毒为首发表现,以肾组织穿刺病理确诊的儿童原发性肾淋巴瘤。2例皆以“多饮、多尿、乏力、呕吐、贫血”为主要症状,双肾肿大,伴低钾、低钙、低磷,代谢性酸中毒等。1例放弃治疗,另外1例经泼尼松、长春新碱、阿糖胞苷＋L-天冬氨酰胺酶(PVA+L-ASP)方案化疗,联合氨甲喋呤、地塞米松、阿糖胞苷鞘内注射、纠酸、补钾、输血及对症支持治疗后,多饮多尿症状缓解,内环境稳定, 复查肾B超无异常发现。一旦怀疑该型恶性淋巴瘤,应尽快肾组织穿刺病理确诊,早期采取综合治疗,包括手术、化疗与放疗、支持疗法等。     

Medullary sponge kidney associated with distal renal tubular acidosis in a 5-year-old girl

Introduction Medullary sponge kidney (MSK) is characterized by cystic dilatation of the inner medullary collecting ducts, which causes the kidneys to resemble a sponge.Case report Although distal renal tubular acidosis (dRTA) is commonly observed in patients with MSK, we report a 5-year-old girl with MSK who had features of both dRTA (nephrocalcinosis, hypercalciuria, hypocitraturia) and proximal tubular dysfunction (hyperuricosuria, impaired tubular phosphate reabsorption and proteinuria).Discussion Metabolic acidosis, hypercalciuria, hypocitraturia, tubular phosphate reabsorption and growth retardation in the patient improved with alkali therapy.     

THE ACIDIFICATION DEFECT IN THE SYNDROME OF RENAL TUBULAR ACIDOSIS WITH NERVE DEAFNESS

Abstract. An 8-year-old boy with renal tubular acidosis and nerve deafness, has been followed for seven years. Repeated studies of his renal acidification defect showed that until the age of six years the tubular defect was mixed, proximal and distal (type 1,2 hybrid). After that age the defect of proximal acidification disappeared and the patient only presented a distal renal tubular acidosis type 1. When this is associated with nerve deafness, it is considered a distinct nosological entity.     

Acute renal failure in the newborn: Incidence and outcome

Objective: To describe an experience from a developing country of newborn renal disease particularly those without advanced neonatal care. Methodology: Prospective evaluation from a referral hospital, North-East of Nigeria between 1 July 1990 and 30 June 1994. Babies admitted for any morbidities who were diagnosed as being in acute renal failure (ARF) during the study period (non-oliguric inclusive). Onset of ARF; day on which oliguria or anuria detected, or serum urea first exceeded 10 mmol/L. Urine output quantitated from carefully bagged urine and suprapubic bladder aspiration, and venous blood regularly obtained for serum electrolytes, urea and creatinine. Fractional excretion of sodium (FE_Na) and renal failure index (RFI) were determined on some babies. Results: Forty-three neonates (M:F; 3.3:1) with ARF, the majority (27) of whom were out-born, and 14, 26 and three were preterm, full-term and post term, respectively. Encountered incidence was 3.9/1000 live births with a high prevalence rate; 34.5/1000 admissions. A significantly greater incidence was seen in the latter half of study; 10.7 vs 53.7/1000, P<0.05. Early ARF occurrence (aged; 0–5 days) in 33 (77%) of babies. The aetiology was comprised of perinatal asphyxia, sepsis, obstructive uropathy and miscellaneous in 53.4%, 32.6%, 9.3% and 4.7%, respectively. Twenty-two (51.2%) deaths occurred; however, the exact causes were indeterminable. Fractional excretion of sodium (FE_Na and renal failure index (RFI) were of <1.75% and ≤2.0, respectively, significantly differentiated sepsis (intrinsic) from perinatal asphyxial (pre-renal) ARF; P<0.01. No case of persistent renal failure occurred. Conclusion: Our FE_Na value (although less than reported in previous literature from affluent societies) remained sensitive (along with RFI) in differentiating aetiological group of ARF. Our data and medical management outcome, despite absence of level-III care, support the need for good resuscitation, careful monitoring and constant re-evaluation. The effect of salbutamol on hyperkalaemia is emphasized.     

Proximal Renal Tubular Acidosis in a Child with Type 1 Glycogen Storage Disease

ABSTRACT. A 6 1/2-year-old Japanese girl with type 1 glycogen storage disease developed a profound metabolic acidosis refractory to bicarbonate renal tubular acidosis and hyperphosphaturia. There was no evidence of distal tubular dysfunction.     

Type 4 Renal Tubular Acidosis (Sub-type 2) Associated with Idiopathic Interistitial Nephritis

ABSTRACT. An 18-month-old girl presenting with anorexia and failure to thrive, was referred for adenoidectomy. Arterial hypertension was discovered on physical examination. Laboratory results revealed hyperkalaemic, hyperchloraemic, metabolic acidosis, with slight azotemia. Urinary aldosterone excretion and plasma renin were decreased. Renal biopsy showed idiopathic interstitial nephritis. The diagnosis of type 4 renal tubular acidosis, sub-type 2, i.e. primary hyporeninaemic secondary hypoaldosteronism was proposed. According to our knowledge, this disease has not previously been reported in young children, but is well known in azotaemic adults. We therefore propose the inclusion of this uncommon renal disease in the differential diagnosis of failure to thrive in childhood.     

RENAL TUBULAR ACIDOSIS ASSOCIATED WITH TYPE III GLYCOGENOSIS

ABSTRACT. Cohen, J. and Friedman, M. (Department of Paediatrics, Whittington Hospital, London, England). Renal tubular acidosis associated with type III glycogenosis. Acta Paediatr Scand, 68: 779, 1979.—Two children who presented with severe failure to thrive were found to have Type III glycogen storage disease. They both also had defects of tubular acidification, an association not previously described. The nature of the tubular lesion is characterized and the explanation and therapeutic implications are discussed.     

PROXIMAL RENAL TUBULAR ACIDOSIS IN TETRALOGY OF FALLOT

ABSTRACT: Rodriguez-Soriano, J., Vallo, A., Chouza, M. and Castillo, G. (Department of Paediatrics, Hospital Infantil de la Seguridad Social, Bilbao, Spain). Proximal renal tubular acidosis in tetralogy of Fallot. Acta Paediatr Scand, 64:671, 1975.–A 9-year-old girl presented with tetralogy of Fallot and moderate metabolic acidosis. Despite a Blalock's fistula there was evidence of chronic hypoxia with cyanosis, clubbing of fingers and toes and very elevated blood hematocrit values. Renal acidification and bicarbonate titration demonstrated the existence of proximal renal tubular acidosis: renal bicarbonate threshold was low (18 mmoles/1) and normal urinary acidification was present at subthreshold serum bicarbonate levels. Following corrective heart surgery, blood acid-base values and renal reabsorption of bicarbonate became normal. A causal relationship between extracellular fluid volume expansion dependent on the high hematocrit and proximal renal tubular acidosis is suggested.     

Renal tubular dysfunction in methylmalonic acidaemia

Renal tubular function was assessed in seven patients with methylmalonic acidaemia not responsive to vitamin B₁₂. Five patients failed to concentrate their urine normally and in these patients the glomerular filtration rate was also reduced. Fractional excretion of sodium was increased in four patients, fractional excretion of potassium in one patient and in three there was a decreased tubular reabsorption of phosphate. Although possibly representing primary tubular damage these findings were thought to be consistent with adaptive changes secondary to the reduced glomerular filtration rate. Two patients had evidence of a defect of urinary acidification and several had a degree of hyporeninaemic hypoaldosteronism suggesting type 4 renal tubular acidosis. In one patient with a mild variant no renal disease was detected. Decreased renal function and tubular abnormalities were common in patients with methylmalonic acidaemia. It is likely that they are linked and essentially secondary to the tubulo-interstitial nephritis that is histologically demonstrable on renal biopsy. The failure of urinary concentrating ability and the disturbed urine acidification will contribute to the metabolic derangement during episodes of decompensation.