Metabolism is the set of chemical reactions that occur in living organisms in order to maintain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories. Catabolism breaks down large molecules, for example to harvest energy in cellular respiration. Anabolism, on the other hand, uses energy to construct components of cells such as proteins and nucleic acids.

The chemical reactions of metabolism are organized into metabolic pathways, in which one chemical is transformed into another by a sequence of enzymes. Enzymes are crucial to metabolism because they allow organisms to drive desirable but thermodynamically unfavorable reactions by coupling them to favorable ones. Enzymes also allow the regulation of metabolic pathways in response to changes in the cell's environment or signals from other cells.

The metabolism of an organism determines which substances it will find nutritious and which it will find poisonous. For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals. The speed of metabolism, the metabolic rate, also influences how much food an organism will require.

A striking feature of metabolism is the similarity of the basic metabolic pathways between even vastly different species. For example, the set of carboxylic acids that are best known as the intermediates in the citric acid cycle are present in all organisms, being found in species as diverse as the unicellular bacteria Escherichia coli and huge multicellular organisms like elephants. These striking similarities in metabolism are most likely the result of the high efficiency of these pathways, and of their early appearance in evolutionary history.

NEED FOR A METABOLISM LABORATORY Inborn errors of metabolism (IEM) are a rare group of disorders that are individually rare but collectively common with clinical presentation ranging from a neonate to adults. They have been long forgotten for reasons unknown. Rate of occurrence has been estimated at 1 in 5000 live births. It is believed that one of the most common reasons for their occurrence among populations is the practice of marriage within the same family (Consanguinity).

Children born to such couples are at a higher risk and are said to be "genetically pre-disposed". The need to screen for an IEM arises out of the fact that most cases take to irreversible effects as time progresses. Emphasis has been laid on early detection and prompt management which have been responsible for alleviating symptoms and preventing complications. Such a screen helps to prevent complications arising out of disorders such as Phenylketonuria, Tyrosinemia, Galactosemia, Hereditary Fructose Intolerance and other IEM. Symptoms of all such disorders could be prevented with dietary restriction of the offending food constituent- for example, Fructose in the case of Hereditary Fructose Intolerance, Tyrosine and Phenylalanine in the case of Tyrosinemia etc. As a matter of fact, neonatal screening is mandatory in the United States, UK and other developed countries. IEM screening could help in the detection of vitamin dependent states such as Biotinidase deficiency which require mainly optimal administration of the deficient vitamin. Such states when left unnoticed progress to fatal convulsive disorders.

Metabolism Laboratory, Apollo Hospitals, Bangalore has a rare distinction of being a referral center for diagnosis of inborn errors of metabolism (IEM) and newborn screening for several hospitals across South India.


Salient features:

• First lab to process 10,000 tests / month
• First lab to initiate Newborn screening in rural areas of Karnataka.
• Laboratory using HPLC / GC-MS for maximum number of clinical applications.
• Newborn screening Quality Assurance from CDC, Atlanta.
• Test panel for cardiac / gastro / renal conditions.
• Customized panels for various metabolic disorders.
• Outsourcing made simpler.
• Publishes 6-8 research papers per year.
• Involved in method development and metabolic research (pathobiochemistry).
• Lab support for various projects, both internal & external.
• Enjoys support from Pediatrics, Neurology,
• Gastroenterology and Cardiology departments.
• Comprehensive, End-to-end solutions for Inborn errors of metabolism (IEM)

• To offer a platform to study these ‘rare’ heritable class of disorders.
• To generate a database with regard to their occurrence rate, management, therapy and outcome in India.
• Create awareness among parents / general public and clinicians to emphasize the need for such a screen in India.
• To identify commonly occurring mutations in the Indian population.

NUMBER OF DISORDERS DETECTED BY THE WORKING GROUP AT THE LAB
Table: Presenting symptoms and defective enzyme/ metabolic defect of the disorders: