Question: What are the symptoms of Bartter syndrome ?
Answer: What are the signs and symptoms of Bartter syndrome? The signs and symptoms associated with Bartter syndrome can vary depending on the form of Bartter syndrome an affected individual has. The antenatal forms (beginning before birth) can be life-threatening, while the classical form, beginning in early childhood, tends to be less severe. The antenatal forms of Bartter syndrome (types I, II and IV) may first be characterized by abnormally high levels of amniotic fluid surrounding the affected fetus (polyhydramnios); premature delivery; and possibly life-threatening salt (sodium-chloride) loss. Affected newborns may have fever, vomiting, diarrhea, failure to thrive, delayed growth, intellectual disability, and/or distinctive facial features (triangular face, prominent forehead, large eyes, protruding ears, and drooping mouth). Individuals with type IV may also have sensorineural deafness (hearing loss caused by abnormalities in the inner ear). Classical Bartter syndrome typically becomes apparent in infancy and is characterized by failure to thrive and constipation in the first year of life. Symptoms may include salt craving, fatigue, muscle weakness, growth delay and developmental delay. Loss of excess sodium chloride through the urine can lead to dehydration, constipation, and increased urine production (polyuria). Loss of excess calcium through the urine (hypercalciuria) can cause weakening of the bones (osteopenia). When this excess calcium becomes deposited in the kidneys, tissue in the kidneys can become hardened (nephrocalcinosis). Low levels of potassium in the blood (hypokalemia) cause the muscle weakness, cramping, and fatigue in affected individuals. The Human Phenotype Ontology provides the following list of signs and symptoms for Bartter syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Abnormal renal physiology 90% Abnormality of metabolism/homeostasis 90% Short stature 90% Hypocalciuria 7.5% Hypomagnesemia 7.5% Abnormality of the choroid - Abnormality of the retinal vasculature - Abnormality of the sclera - Autosomal recessive inheritance - Chondrocalcinosis - Congenital onset - Constipation - Decreased glomerular filtration rate - Dehydration - Diarrhea - Edema - Failure to thrive - Fetal polyuria - Fever - Frontal bossing - Generalized muscle weakness - Global glomerulosclerosis - Heterogeneous - Hydrops fetalis - Hyperactive renin-angiotensin system - Hyperaldosteronism - Hypercalciuria - Hyperchloridura - Hypernatriuria - Hyperprostaglandinuria - Hypochloremia - Hypokalemia - Hypokalemic hypochloremic metabolic alkalosis - Hypokalemic metabolic alkalosis - Hyponatremia - Hyporeflexia - Hyposthenuria - Hypotension - Impaired platelet aggregation - Impaired reabsorption of chloride - Increased circulating renin level - Increased serum prostaglandin E2 - Increased urinary potassium - Intellectual disability - Large eyes - Low-to-normal blood pressure - Macrocephaly - Macrotia - Motor delay - Muscle cramps - Muscular hypotonia - Nephrocalcinosis - Osteopenia - Paresthesia - Polydipsia - Polyhydramnios - Polyuria - Premature birth - Prominent forehead - Reduced renal corticomedullary differentiation - Renal insufficiency - Renal juxtaglomerular cell hypertrophy/hyperplasia - Renal potassium wasting - Renal salt wasting - Seizures - Sensorineural hearing impairment - Small for gestational age - Tetany - Triangular face - Tubulointerstitial fibrosis - Vomiting - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD

Question: What causes Bartter syndrome ?
Answer: What causes Bartter syndrome? Bartter syndrome may be caused by mutations in any one of several genes; the genetic cause in each case corresponds to the type of Bartter syndrome each affected individual has. Types I, II and IV typically result in the antenatal forms of Bartter syndrome (beginning before birth) while type III results in classical Bartter syndrome (usually beginning in early childhood). Type I results from mutations in the SLC12A1 gene; type II from mutations in the KCNJ1 gene; type III from mutations in the CLCNKB gene; and type IV from mutations in the BSND gene, or from a combination of mutations in the CLCNKA and CLCNKB genes. In some people with Bartter syndrome, the genetic cause of the disorder remains unknown; there may be other genes that cause the condition that have not yet been identified. All of these genes are essential for normal kidney function - they are involved in the kidneys' abilities to reabsorb salt. Abnormal changes in these genes impair these abilities, allowing for the loss of excess salt through the urine and also affecting the reabsorption of other things including potassium and calcium. The resulting imbalance of these in the body lead to the signs and symptoms of Bartter syndrome.
Source: GARD

Question: Is Bartter syndrome inherited ?
Answer: How is Bartter syndrome inherited? Bartter syndrome is inherited in an autosomal recessive manner, which means that both copies of the disease-causing gene (one inherited from each parent) have a mutation in an affected individual. Parents who each carry one mutated copy of the gene are referred to as carriers and typically do not have signs or symptoms of the condition. When two carriers for an autosomal recessive condition have children, each child has a 25% (1 in 4) risk to have the condition, a 50% (1 in 2) risk to be a carrier like each of the parents, and a 25% chance to not have the condition and not be a carrier. Click here to visit the Genetic Home Reference Web site and view an illustration that demonstrates autosomal recessive inheritance.
Source: GARD

Question: How to diagnose Bartter syndrome ?
Answer: How is Bartter syndrome diagnosed? Bartter syndrome is usually diagnosed after a combination of tests are performed on an individual with the signs and symptoms of the condition. Blood test results in an affected individual typically show low blood potassium levels (with normal blood pressure); low blood chloride levels; and an acid/base balance that is skewed towards the base (i.e. the blood is more alkaline than usual). High levels of the hormones renin and aldosterone in the blood would also support the diagnosis. Urine test results that would support the diagnosis include high levels of potassium and chloride, suggesting that the kidneys have impaired ability to control the concentrations of these electrolytes. A positive genetic test result would confirm the diagnosis. Is genetic testing available for Bartter syndrome? Yes, genetic testing for Bartter syndrome is available. GeneTests lists the names of laboratories that are performing clinical genetic testing for Bartter syndrome. To view a list of the clinical laboratories performing testing for each type of Bartter syndrome, click on the appropriate link below: Antenatal Bartter syndrome type I Antenatal Bartter syndrome type II Bartter syndrome type III (Classical Bartter syndrome) Bartter syndrome type IVA (Infantile Bartter Syndrome with Sensorineural Deafness) Bartter syndrome type IVB Please note that most of the laboratories listed through GeneTests do not accept direct contact from patients and their families; therefore, individuals interested in learning more will need to work with a health care provider or a genetics professional.
Source: GARD

Question: What are the treatments for Bartter syndrome ?
Answer: How might Bartter syndrome be treated? Treatment of Bartter syndrome depends on the type of the syndrome that the affected individual has, but it primarily focuses on preventing the loss of too much of potassium from the body. This may include oral potassium (K) supplements, medication such as indomethacin, and potassium-sparing diuretics. In high-stress situations such as illness or trauma, blood electrolyte levels can change rapidly, which may require immediate intravenous treatment. Genetic counseling may benefit affected individuals and their families. eMedicine has an article containing additional, thorough information about the management and treatment of Bartter syndrome. Click here to view this information.
Source: GARD