Causes and risk factors
Bartter syndrome is a rare disorder caused due to mutation of genes. It is an autosomal recessive type disease. The genes usually involved are KCNJ1, CLCNKB, SLC12AI and BSND. These genes play a role in absorption of salt by the kidney tissues. Mutation of these genes impairs the function of kidney of absorbing the salt and its transportation. Along with this, reabsorption of other charged atoms is also hampered. The renin aldosterone axis is hampered; this leads to potassium wasting and electrolyte imbalance which in turn leads to alkalosis.
Clinical presentation:
Bartter syndrome has various classifications. Depending upon the genes involved, they are classified as type I, type II, type III, and type IV. Type I is caused due to mutation of gene SLCI2AI, while type II is caused due to mutation in gene KCNJ1; type III and type IV is characterized by mutation in gene CLCNKB and BSND respectively. Depending upon the age of onset and severity of complaints, Bartter syndrome is also classified as antenatal form and classical form. In antenatal type, the complaints appear before birth and the complaints are life-threatening. In childhood form, the complaints appear after birth and the suffering is less severe. Bartter syndrome during pregnancy can cause increase in the volume of the amniotic fluid thus increasing the risk for premature birth of the baby. It hampers the growth of the child. The bones become weak as large amount of calcium is excreted through the body. Along with this, excess of accumulation in the kidney can lead to formation of stones and hardening of the kidney tissues. Dehydration, constipation, and increased frequency of urine, weak muscles, cramps in muscles, and fatigue are the other symptoms seen. Electrolyte imbalance leads to low blood pressure, and growth failure is seen in some people.
Investigations:
Diagnosis is done on the basis of the symptoms narrated by the patient. A detailed physical examination and certain investigations are carried out. Blood tests indicating low levels of potassium in the body can lead can to suspect Bartter syndrome. Decreased levels of chloride and potassium, levels of plasma is seen. Urine analysis is carried out. Potassium, chloride, and calcium levels in urine are measured. Serum electrolyte levels along with kidney biopsy are other investigations which are advised. Genetic testing, although rare can be advised. Certain other imaging tests can also be advised as per the presentation of the patient.
Treatment:
Eating potassium rich food and intake of potassium supplements is the main line of treatment. Along with potassium supplements, in certain cases salt and magnesium supplements are also advised. Medication which will prevent the loss of electrolytes from urine is prescribed. Low dose of ACE inhibitors or NSAIDs are other drugs of choice. Certain other treatment modes can also be adopted as per the presentation.
Other Modes of treatment:
Certain other modes of treatment can also be helpful in coping up with the symptoms. Taking into consideration the symptoms in a holistic way, homoeopathy can offer a good aid for the relief of the symptoms. The Ayurvedic system of medicine which uses herbs and synthetic derivates can also be beneficial in combating the complaints.
Facts and Figures:
The incidence of Bartter syndrome is 1 in 1 million people worldwide.
