Bartter's syndrome: a neonatal presentation (a case report).CP Contractor, SD Mehta, SU Wagle, PG Desphande, SF Irani
Department of Paediatrics, K.E.M. Hospital, Seth G.S. Medical Collage, Parel, Bombay.
Keywords: Bartter′s Disease, diagnosis,genetics,Case Report, Consanguinity, Electrolytes, urine,Follow-Up Studies, Human, Indomethacin, administration &dosage,Infant, Newborn, Infant, Premature, Diseases, diagnosis,genetics,
Bartter's syndrome is a rare metabolic disorder resulting due to excess loss of chlorides from the nephron. It is characterised by persistent hypokalemia, hypochloremia, metabolic alkalosis, hyperreninemia with hyperaidosteronism in the absence of hypertension and refractoriness of angio tension-II.
We are reporting herewith a case of Bartter's syndrome diagnosed in the neonatal period. There are very few reports of neonatal presentation in the world literature.
A 34 week premature baby was born of second degree consanguineous marriage by an emergency LSCS for abruptio placentae. The mother was gravida 2, para 2 and had polyhydramnios during this as well as previous pregnancy. The investigations done during antenatal period failed to reveal the cause of polyhydramnios. The baby required no resuscitation at birth and weighed 2.1 kg. The clinical and radiological examination did not reveal any malformations of the gut or spine. The previous sibling born of full term normal delivery had a history of failure to thrive during neonatal period and died of severe dehydration of unexplained etiology at the age of 1 ½ months.
The present case also did not show a satisfactory weight gain in the first two weeks of life, inspite of supervised feeding. The baby had occasional vomiting with poor activity and weak suck. The systemic examination was normal. There was no evidence of sepsis detected on septic screen. The investigation findings are presented in [Table - 1], [Table - 2] & [Table - 3]. The metabolic parameters revealed hypokalemia, hypochloremic metabolic alkalosis with hyponatremia. Further investigations showed excessive loss of sodium, potassium and chloride in urine. Hence Bartter's syndrome was suspected. The child was normotensive. The diagnosis was confirmed by raised plasma renin activity and plasma aidosterone level [Table - 3].
The child was put on potassium (12 meq/kg/day) and sodium (2 gm/lg/day) supplementation initially and subsequently indomethaciri (2 mglkg/day) was added to the regimen in three divided doses. On this therapy, the child demonstrated remarkable improvement in activity and weight gain, The sodium and potassium requirements reduced after indomethacin therapy.
The child when followed up at the age of 4 months was developmentally normal and had thrived well.
The biochemical picture of hypokalemic hypochloremic alkalosis suggests possibility of prima or secondary hyperaidolesteronism. Of the former, primary mineralo-corticold excess and laddle's syndrome are excluded by absence of hypertension and high or normal plasma sodium levels. In the latter, when no cause can be identified such as vomiting, diarrhoea, abuse of diuretics or laxatives the conditions that remain to be differentiated are Bartter's syndrome and Gitelman's syndrome (primary renal magnesium wasting). Absence of tetany and normal serum calcium rule our of Gitelman's syndrome.
Since the description of this syndrome in 1962 by Bartter et al, over 100 cases have been reported in the literature describing a wide spectrum of clinical and biochemical features. They are hypereateemia, hyperphosphatemia, hypercalciuria, nephrocalcinosis, rickets, magnesium deficiency, defective renal tubular acidification, excess renal prostaqiandin production, defects in platelet aggregation, and juxtaglomerular and renomedullary cell hyperplasia. Thomas et al have described typical characteristic facies in two infants with this syndrome.
The majority of patients present with failure to thrive vomiting and constipation during the first 2 years of life.
History of polyhydramnios in a previous sib with death following dehydration may suggest autosomal recessive pattern of inheritance of this syndrome,.
There is no unifying hypothesis that explains the range of abnormalities seen in Bartter's syndrome. The most accepted being the primary abnormality in electrolyte transfer across the muscle, RBC and renal tubular cell membrane. The defective chloride reabsorption in ascending limb or Henle's loop is the most proximal defect in the kidney.
The treatment of Bartter's syndrome consists of sodium and potassium supplementation with indomethacin in doses of 2-5 mg/kg/day. Renin suppressing agents like methyIdopa and propranol do not appear to be useful. Spiranolactone and triameterence have also been used.
Indomethacin needs to be continued till growth is complete.
The authors wish to thank Dr. GB Parulkar, Dean, King Edward Memorial Hospital, for allowing us to publish the above article.
[Table - 1], [Table - 2], [Table - 3]