Gitelman’s syndrome and pregnancy: new potential pathophysiological influencing factors, therapeutic approach and materno-fetal outcome

Anesthetic Considerations for Cesarean Delivery in a Parturient With Severe Gitelman Syndrome

Gitelman syndrome is an autosomal recessive inherited disorder that impairs the function of thiazide-sensitive sodium-chloride cotransporters in the distal convoluted tubule of the nephron. During labor and delivery, avoidance of sympathetic overactivity, meticulous hemodynamic monitoring, and expedited repletion of potassium and magnesium are required to avoid adverse outcomes. We present a parturient with severe Gitelman syndrome, requiring continuous electrolyte and fluid infusions, who underwent successful cesarean delivery. Potential severe morbidity was avoided with multidisciplinary planning and management.

Gitelman Syndrome in Pregnancy: A Clinical Challenge

PURPOSE

 Disease progress may be affected by pregnancy-related changes, and underlying conditions may also affekt pregnancy outcomes in women with Gitelman syndrome (GS). Case presentation A 35-year-old woman with GS (gravida 2 para 1) was referred to our hospital to start routine antenatal care follow-up at 6 weeks of gestation. At the age of 31, she had been diagnosed with GS after her first uneventful pregnancy. Upon early admission, her serum Mg+level was 0.51 mmol/L and her serum K+level 2.7 mmol/L with normal kidney function tests. She was already taking oral combined potassium citrate and potassium bicarbonate supplementation once a day before pregnancy. At the eighth gestational week, the medication was changed to an oral potassium color sachet of 1.5 gram per day until labor because of the insufficient dosage to maintain optimum potassium levels. She was also taking 365 milligrams of oral magnesium oxide twice a day before and during pregnancy. In the third trimester of the pregnancy, her serum Mg+level was 0.48 mmol/L and serum K+level 2.8 mmol/L. Because of the previous uterine surgery history, she underwent an elective cesarean operation at 39 weeks' gestation under spinal anesthesia and delivered a healthy 3090-gram female infant.

CONCLUSION

 Increased need for potassium and magnesium supplementation should be the critical considerations when managing pregnant patients with GS.

Clinical and laboratory features of female Gitelman syndrome and the pregnancy outcomes in a Chinese cohort

AIM

Gitelman syndrome (GS) is a rare inherited salt-losing renal tubulopathy. Data on clinical features and the pregnancy outcome for female GS patients in a large cohort are lacking. The study was aimed to explore the phenotype and pregnant issue for female GS patients.

METHODS

GS cases from the National Rare Diseases Registry System of China (NRSC) were collected, and detailed clinical, laboratory and genetic data were analysed. Articles on pregnancy in GS were also systemically reviewed.

RESULTS

A total of 101 GS patients were included; among them, 42.6% were female and 79.2% showed hypomagnesaemia. A lower proportion of female patients presented before 18 years of age, with less frequently reported polyuria, higher serum potassium and less urine sodium and chloride excretions. There was no gender difference in the sodium-chloride cotransporter (NCC) dysfunction evaluated by hydrochlorothiazide test. Twelve of the 43 female GS patients delivered after disease symptom onset, and their pregnancies were generally uneventful. As a group, pregnant GS patients had lower potassium levels in the first-trimester (P = .002) requiring higher potassium supplementation. After delivery, serum potassium (P = .02) and magnesium (P = .03) increased significantly. Both caesarean section and vaginal delivery were safe.

CONCLUSION

Female GS patients may have a less severe phenotype with generally favourable outcomes of pregnancy. Intensive monitoring and increased potassium supplementation are necessary during pregnancy, especially in the first-trimester.

Gitelman syndrome in pregnancy: a case series

OBJECTIVE

To evaluate maternal and fetal outcomes in women with Gitelman syndrome (GS).

METHODS

Retrospective analysis of the clinical data of five patients with the clinical diagnosis of GS during pregnancy, who were admitted to Beijing Shijitan Hospital, Capital Medical University between 2013 and 2019, was conducted.

RESULTS

Five women with GS during pregnancy who finally gave birth to a total of eight newborns have been included. Three cases were primiparas and two cases were multiparas. Two cases were diagnosed before pregnancy and three cases were diagnosed in first or second trimester. The primary treatment was oral or intravenous electrolytes supplement. Three patients delivered through the vagina, and shoulder dystocia occurred in one patient. Two patients delivered by cesarean section, with one because of symptom of limb weakness during the course of labor and the other owing to gestational diabetes with fetal macrosomia. Postpartum hemorrhage and urinary retention were not reported in these cases. In perinatal period all the infants had good outcome. The children, aged between six months and five years, were healthy and well-developed during follow-up.

CONCLUSION

The maternal and perinatal outcome is usually favorable. We should pay attention to electrolyte examination in the first trimester in order to diagnose and manage the GS efficiently. Well-controlled patients with Gitelman syndrome can deliver through the vagina.

The challenges of diagnosis and management of Gitelman syndrome

Gitelman syndrome is an inherited tubulopathy characterized by renal salt wasting from the distal convoluted tubule. Defects in the sodium chloride cotransporter (encoded by SLC12A3) underlie this autosomal recessive condition. This article focuses on the specific challenges of diagnosing and treating Gitelman syndrome, with use of an illustrative case report. Symptoms relate to decreased serum potassium and magnesium levels, which include muscle weakness, tetany, fatigue and palpitations. Sudden cardiac deaths have been reported. Making a diagnosis may be difficult given its rarity but is important. A knowledge of the serum and urine biochemical picture is vital to distinguish it from a broad differential diagnosis, and application of genetic testing can resolve difficult cases. There is a group of Gitelman syndrome heterozygous carriers that experience symptoms and electrolyte disturbance and these patients should be managed in a similar way, though here genetic investigations become key in securing a difficult diagnosis. Potassium and magnesium replacement is the cornerstone of treatment, though practically this can be hard for patients to manage and often does not fully relieve symptoms even when serum levels are normalized. Challenges arise due to the lack of randomized controlled trials focussing on treatment of this rare disease; hence, clinicians endorse strategies in line with correction of the underlying pathophysiology such as sodium loading or pharmacological treatments, which seem to help some patients. Focussed dietary advice and knowing the best tolerated preparations of potassium and magnesium medications are useful tools for the physician, as well as an awareness of the specific burdens that this patient group face in order to signpost appropriate support.

Gitelman Syndrome: A Rare Cause of Seizure Disorder and a Systematic Review

Gitelman syndrome is one of the few inherited causes of metabolic alkalosis due to salt losing tubulopathy. It is caused by tubular defects at the level of distal convoluted tubules, mimicking a thiazide-like tumor. It usually presents in late childhood or in teenage as nonspecific weakness, fatigability, polyuria, and polydipsia but very rarely with seizures. It is classically associated with hypokalemia, hypomagnesemia, hypocalciuria, hyperreninemia, and hyperaldosteronism. However, less frequently, it can present with normal magnesium levels. It is even rarer to find normomagnesemic patients of GS who develop seizures as the main complication since hypomagnesemia is considered the principal etiology of abnormal foci of seizure-related brain activity in GS cases. Interestingly, patients with GS are oftentimes diagnosed during pregnancy when the classic electrolyte pattern consistent with GS is noticed. Our case presents GS with normal serum magnesium in a patient, with seizures being the main clinical presentation. We also did a comprehensive literature review of 122 reported cases to show the prevalence of normal magnesium in GS cases and an overview of clinical and biochemical variability in GS. We suggest that further studies and in-depth analysis are required to understand the pathophysiology of seizures in GS patients with both normal and low magnesium levels.

[Management of Gitelman syndrome during pregnancy reporting 12 cases]

INTRODUCTION

Gitelman syndrome is a rare hereditary renal tubulopathy, responsable of hypokalemia and hypomagnesaemia-related ionic disorders, which management is poorly codified during pregnancy. We report 12 cases of pregnancies with Gitelman syndrome and we compare our data with those of literature.

MATERIAL AND METHODS

It is a report of 12 pregnancies in 5 patients with Gitelman syndrome between 2002 and 2016. Follow up and outcome of pregnancy, delivery modalities and maternal-fetal prognosis have been collected.

RESULTS

In our serie, maximum kaliemie observed was 3.4mmol/L, with an average potassium, over all pregnancies of 2.3mmol/L. Oral potassium and magnesium supplementation at the end of pregnancy were 8900mg/day and 460mg/day, respectively. There were no serious maternal complications. Two pregnancies were complicated by intrauterine growth retardation in a context of preeclampsia. There is a large disparity in the methods of anesthetic management of these patients. Materno-fetal prognosis at 1 month post-partum is good.

CONCLUSION

Gitelman syndrome is a rare pathology where there is a lack of homogeneity in management of pregnancy. Monitoring of monthly ionogram is necessary. The goal is to obtain stable, non-symptomatic kaliemias, which will never be standardized even in increasing treatment. The most important is to inform and detect situations at risk of decompensation, including vomiting or the use of certain anesthetics. In agreement with literature data, monitoring of fetal growth and the amount of amniotic fluid in the third trimester is still warranted. These pregnancies require the development of a common care in multidisciplinary consultation meeting.

Gitelman's Syndrome: characterization of a novel c.1181G>A point mutation and functional classification of the known mutations

We have investigated the mechanisms by which a novel missense point mutation (c.1181G>A) found in two sisters causes Gitelman's syndrome by impairing the sodium chloride co-transporter (NCC, encoded by SLC12A3 gene) function. The cDNA and in vitro transcribed mRNA of either wild-type or mutated SLC12A3 were transfected into HEK293 cells and injected into Xenopus laevis oocytes, respectively. The expression, maturation, trafficking, and function of the mutated and wild-type NCC were assessed by Western blotting, immunohistochemistry and ²²Na⁺ uptake studies. By immunoblotting of lysates from HEK293 cells and oocytes expressing wild-type NCC, two NCC-related bands of approximately 130 kDa and 115 kDa, corresponding to fully and core-glycosylated NCC, respectively, were identified. In contrast, the mutant NCC only showed a single band of approximately 115 kDa, indicating impaired maturation of the protein. Moreover, oocytes injected with wild-type NCC showed thiazide-sensitive ²²Na⁺ uptake, which was absent in those injected with the mutant NCC. The novel mutation was discussed in the context of the functionally characterized NCC mutations causing Gitelman's syndrome, which fit into five classes. In conclusion, the functional characterization of this novel Gly394Asp NCC and its localization on the NCC structure, alongside that of previously known mutations causing Gitelman's syndrome, may provide novel information on the function of the different domains of the human NCC.

Two cases of successful pregnancy in patients with Gitelman's syndrome

Gitelman's syndrome (GS) is a distal convoluted tubule (DCT) defect clinically characterized by hypokalemic metabolic alkalosis. Pregnancy in women with GS often results in severe hypomagnesemia and hypokalemia. We report two cases of successful pregnancies, after previous fetal loss, in patients with GS managed with aggressive oral and intravenous electrolyte repletion. These cases illustrate increased potassium and magnesium requirements over the course of the pregnancies and are notable due to the high doses of electrolytes required. They also demonstrate the possibility of successful pregnancy outcomes with frequent laboratory monitoring and aggressive titration of electrolyte replacement either orally or intravenously to maintain appropriate serum levels necessary to provide a suitable environment for fetal development.

Gitelman syndrome: consensus and guidance from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Gitelman syndrome (GS) is a rare, salt-losing tubulopathy characterized by hypokalemic metabolic alkalosis with hypomagnesemia and hypocalciuria. The disease is recessively inherited, caused by inactivating mutations in the SLC12A3 gene that encodes the thiazide-sensitive sodium-chloride cotransporter (NCC). GS is usually detected during adolescence or adulthood, either fortuitously or in association with mild or nonspecific symptoms or both. The disease is characterized by high phenotypic variability and a significant reduction in the quality of life, and it may be associated with severe manifestations. GS is usually managed by a liberal salt intake together with oral magnesium and potassium supplements. A general problem in rare diseases is the lack of high quality evidence to inform diagnosis, prognosis, and management. We report here on the current state of knowledge related to the diagnostic evaluation, follow-up, management, and treatment of GS; identify knowledge gaps; and propose a research agenda to substantiate a number of issues related to GS. This expert consensus statement aims to establish an initial framework to enable clinical auditing and thus improve quality control of care.

HELLP syndrome in a pregnant patient with Gitelman syndrome

Gitelman syndrome is characterized by hypokalemia, metabolic alkalosis, hypocalciuria, and hypomagnesemia. The clinical course of Gitelman syndrome in pregnant women remains unclear, but it is thought to be benign. We report here the first Korean case of atypical eclampsia in a 31-year-old who was diagnosed with Gitelman syndrome incidentally during an antenatal screening test. The patient did well during pregnancy despite significant hypokalemia. At 33 weeks' gestation, the patient exhibited eclampsia, hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome, and renal insufficiency without significant hypertension or proteinuria. We explain this unusual clinical course through a review of the relevant literature.

Gitelman syndrome in a South African family presenting with hypokalaemia and unusual food cravings

BACKGROUND

Gitelman syndrome (GS) is an autosomal recessive renal tubular disorder characterised by renal salt wasting with hypokalaemia, metabolic alkalosis, hypomagnesaemia and hypocalciuria. It is caused by mutations in SLC12A3 encoding the sodium-chloride cotransporter on the apical membrane of the distal convoluted tubule. We report a South African family with five affected individuals presenting with hypokalaemia and unusual food cravings.

METHODS

The affected individuals and two unaffected first degree relatives were enrolled into the study. Phenotypes were evaluated through history, physical examination and biochemical analysis of blood and urine. Mutation screening was performed by sequencing of SLC12A3, and determining the allele frequencies of the sequence variants found in this family in 117 ethnically matched controls.

RESULTS

The index patient, her sister, father and two aunts had a history of severe salt cravings, fatigue and tetanic episodes, leading to consumption of large quantities of salt and vinegar. All affected individuals demonstrated hypokalaemia with renal potassium wasting. Genetic analysis revealed that the pseudo-dominant pattern of inheritance was due to compound heterozygosity with two novel mutations: a S546G substitution in exon 13, and insertion of AGCCCC at c.1930 in exon 16. These variants were present in the five affected individuals, but only one variant each in the unaffected family members. Neither variant was found in any of the controls.

CONCLUSIONS

The diagnosis of GS was established in five members of a South African family through clinical assessment, biochemical analysis and mutation screening of the SLC12A3 gene, which identified two novel putative pathogenic mutations.

Gitelman syndrome during pregnancy – from diagnosis to treatment: a case series and review of the literature

Objective: Gitelman syndrome (GS) is a rare renal disease, originating from a defect in the Na-Cl co-transporter in the distal tubule, which causes hypokalemia, hypomagnesemia, hypocalciuria, metabolic alkalosis and low-normal blood pressure. Mild hypokalemia of pregnancy is physiological. Fatigue, nausea, vomiting, polyuria and low blood pressures are also common complaints associated with a normal pregnancy. Therefore, the diagnosis of an organic renal disorder, i.e., GS, may go undetected, until severe hypokalemia and possible life-threatening cardiac arrhythmias develop. Maternal consequences are obvious. The possibility of fetal pathology remains unclear.

Study design: In this study, we describe nine pregnancies in seven women with a clinical diagnosis of GS. Nearly all women were diagnosed initially during pregnancy. We describe their clinical presentation, serum and urine electrolyte levels during pregnancy and immediately post-partum, their treatment and pregnancy outcome.

Results: Fetal pregnancy outcomes were mostly favorable. While it is likely that women suffering from GS do not require special fetal surveillance, they are at high risk for electrolyte depletion and thus aggravation of GS during pregnancy.

Conclusion: Clinical suspicion of GS should arise in all women presenting with symptomatic hypokalemia. Once the diagnosis is made, adequate supplementation and routine maternal monitoring should ensue.

Gitelman syndrome and pregnancy

Gitelman syndrome (GS) is an autosomal-recessive condition characterized by hypokalemia, hypomagnesemia and hypocalciuria. Very little information is available in the literature to guide the management of pregnant patients with GS. We report a case of a 27-year-old woman with GS who became pregnant and despite persistent hypokalemia and hypomagnesemia during pregnancy and labor, had a successful maternal and fetal outcome.