Childhood Bartter's syndrome: An Indian case series

Schizophrenia-like psychosis and gitelman syndrome: a case report and literature review

Introduction

Gitelman syndrome(GS) is a rare inherited tubular disorder which is characterized by hypokalemia, metabolic alkalosis, hypomagnesemia, and hypocalciuria. Here, we report a case of schizophrenia-like psychosis concomitant with GS and related literatures are reviewed.

Case description

An 18-year-old male patient with 1-week history of auditory hallucinations, sense of insecurity, delusions of reference and feelings of being followed and controlled by others unknown, insomnia was admitted to Psychiatry department in December, 2013. Hypokalemia and hypomagnesemia were noted. He was diagnosed as schizophrenia-like psychosis. Treatment with paliperidone at the dose of 6 mg/day and magnesium and potassium supplementations was commenced. However, electrolyte disturbances failed to improve following psychosis remission. Therefore, other underlying diseases resulting in electrolyte disturbances were suspected. Along with hypokalemia and hypomagnesemia, additional investigation showing metabolic alkalosis, hypocalciuria, renal loss of potassium, were consistent with GS. Gene analysis revealed this patient carried out c. 2687 G > A homozygous mutation of exon 23 in the SLC12A3 gene which led to p.Arg896Gln. Eventually, GS was identified. Thus, additional spironolactone (40 mg/day) combined with increased doses of oral potassium chloride sustained-release tablets (3.0 g/day) and potassium magnesium aspartate (0.3 g/day) were administered. During next half a year, fatigue resolved, paliperidone gradually tapered and eventually discontinued while psychosis maintained complete remission. His serum potassium was near normal (3.2–3.5 mmol/L), hypomagnesemia significantly improved (0.57–0.67 mmol/L).

Discussion and evaluation

Electrolyte abnormalities secondary to GS might cause or contribute to development of neuropsychiatric symptoms. In turn, hypokalemia was common among acute psychiatric inpatients. As a consequence, when concomitant with psychosis, GS was readily concealed.

Conclusion

Electrolyte disturbances are common in acute psychiatric patients. However, when electrolyte disturbances are not improved following psychosis remission, other underlying diseases such as GS should be considered.

Clinical profile and outcome of renal tubular disorders in children: A single center experience

Tubular disorders form a significant proportion of pediatric kidney diseases and are an important differential diagnosis of failure to thrive (FTT) in children. Data regarding their outcome is scarce from India. We evaluated the clinical profile of these children and studied the outcome in terms of their growth and renal failure. This is a retrospective longitudinal study of all children with renal tubular disorders attending a tertiary care pediatric nephrology center from 2005 to 2010. Growth and renal outcomes were assessed by Z scores and estimated glomerular filtration rate at diagnosis and. The common disorders encountered were distal renal tubular acidosis (d-RTA) (44%), Bartter-like (Bartter's and Gitelman) syndromes (22%) followed by hereditary Fanconi syndrome (cystinosis and idiopathic Fanconi syndrome) (13%) and few cases of nephrogenic diabetes insipidus, hypophosphatemic rickets and idiopathic hypercalciuria. Male: female ratio was 1.22. The median age at diagnosis was 1.5 (range 0.13-11) years. Growth failure was the presenting feature in 86% of children followed by polyuria (60%) and bone deformities (47%). In 60% of children with hereditary Fanconi syndrome, nephropathic cystinosis was diagnosed, all of whom progressed to stage III chronic kidney disease (CKD) within 3.41 ± 1.42 years. With appropriate therapy, catch-up growth was noted in d-RTA and Bartter syndrome. Renal tubular disorders usually present with FTT. d-RTA is the most common etiology followed by Bartter-like syndrome. Renal function is preserved in all these disorders except for nephropathic cystinosis, who ultimately progressed to CKD. With appropriate and inexpensive therapy, these children do grow well.

Genetic analysis in Bartter syndrome from India

Bartter syndrome is a group of inherited, salt-losing tubulopathies presenting as hypokalemic metabolic alkalosis with normotensive hyperreninemia and hyperaldosteronism. Around 150 cases have been reported in literature till now. Mutations leading to salt losing tubulopathies are not routinely tested in Indian population. The authors have done the genetic analysis for the first time in the Bartter syndrome on two cases from India. First case was antenatal Bartter syndrome presenting with massive polyuria and hyperkalemia. Mutational analysis revealed compound heterozygous mutations in KCNJ1(ROMK) gene [p(Leu220Phe), p(Thr191Pro)]. Second case had a phenotypic presentation of classical Bartter syndrome however, genetic analysis revealed only heterozygous novel mutation in SLC12A gene p(Ala232Thr). Bartter syndrome is a clinical diagnosis and genetic analysis is recommended for prognostication and genetic counseling.

Gitelman's syndrome: Rare presentation with growth retardation

Gitelman's syndrome is an autosomal recessive disorder characterized by hypokalemic metabolic alkalosis, hypokalemia, hypomagnesaemia, hypocalciuria, hyperreninemia and without hypertension. Gitelman's syndrome is caused by mutations of the SLC12A3 gene, which encodes the Na/Cl co-transporter (NCCT) in the distal convoluted tubule. Majority of cases manifest during adolescence or adulthood and growth retardation is not the common feature. We report a rare presentation of Gitelman's syndrome in a four-year-old boy with growth retardation.