Related Experiment Video
Updated: Jun 4, 2025

A Novel Method: Super-selective Adrenal Venous Sampling
Published on: September 15, 2017
Cracking the code of aldosterone synthase deficiency: bridging genetics and biochemistry: a case report
Lekha Priyadharshini Kamarajan1, Mala Mahto1, Sushil Kumar1
1Department of Biochemistry, AIIMS Patna, Patna, Bihar, India.
Objective:
Aldosterone synthase deficiency (ASD) is a rare autosomal recessive inherited disease with an overall clinical phenotype of failure to thrive, vomiting, severe dehydration, hyperkalemia, and hyponatremia. Mutations in the CYP11B2 gene encoding AS are responsible for the occurrence of ASD. Defects in CYP11B2 gene have only been reported in a limited number of cases worldwide. Due to this potential life-threatening risk, a comprehensive hormonal investigation followed by genetic confirmation is essential for the clinical management of offspring.
Methods:
We report a case of a newborn who was found to have persistent hyponatremia, hyperkalemia, low aldosterone level, raised renin levels, normal cortisol, and normal 17 hydroxyprogesterone level, suggesting the diagnosis of isolated ASD.
Results:
Genetic report was suggestive of isolated ASD caused by a novel base pair deletion in exon 3, homozygous CYP11B2 variant (chr8:g.142915123_142915125del; depth: 124x d) (p.Lys175del; ENST00000323110.2). After initial steps of rehydration and salt restoration, the child was started on oral tablet fludrocortisone. The child responded well and showed a good gain in growth and development.
Discussion:
We elaborate on the biochemical and genetic work-up performed and describe potential pitfalls in CYP11B2 sequencing due to its homology to CYP11B1.
Related Concept Videos
Adrenal Gland Disorders
Adrenal insufficiency, characterized by insufficient cortisol and aldosterone production, leads to conditions like Addison's disease. This disorder, affecting the adrenal cortex, exhibits symptoms such as skin bronzing, dehydration, low blood pressure, fatigue, and weight loss. Congenital adrenal hyperplasia, a genetic ailment causing...
Antihypertensive Drugs: Potassium-Sparing Diuretics
ATP Synthase: Structure
ATP Synthase: Mechanism
Hydrolysis of ATP
If one phosphate group is removed, a molecule of ADP—adenosine diphosphate—remains, along with inorganic phosphate. ADP can be further hydrolyzed to AMP—adenosine...
Renal Tubule and Collecting Duct
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...

