a. Trimethylaminuria

Trimethylaminuria also called fish odor syndrome or TMAU is a genetic disease. It is due to abnormal excretion of trimethylamine in the breath, urine, sweat, saliva and vaginal secretions. The odor produced is similar to decaying fish. The smell consists of sulfur compounds, plus nitrogen compounds (amines). The trimethylamine is made by bowel bacteria that break down certain amino acids, carnitine and choline that are in high concentrations in marine fish, egg yolks, certain beans and liver.

b. Maple Syrup Urine Disease

Maple syrup urine disease or MSUD refers to a rare inherited metabolic condition. The first form results from a deficient enzyme (branched-chain alpha-keto acid dehydrogenase, BCKD) necessary for the breakdown of the amino acids leucine, isoleucine, and valine. Without this enzyme, these amino acids build up to toxic levels in the body. If left untreated, this leads to brain damage and progressive nervous system degeneration in infants. Babies that suffer from the mild form have a sugary smell. Adults may have a burned sugar smell to urine. There second form responds well to the vitamin thiamine. It is reported that the patients smell like caramel, maple syrup or have a malty odor.

c. Phenylketunuria

Phenylketunuria or PKU is another inherited metabolic disorder. In this case the body cannot completely break down the protein phenylalanine because it lacks the enzyme phenylalanine hydroxylase. Because of this, phenylalanine builds up in the body’s cells and causes nervous system and brain damage. High levels of phenylalanine leads to increased levels of phenylketones in the blood which are excreted in the urine. The person may present a musty, mousy, wolflike, barny, horsey or stale smell.

d. Multiple Acyl-CoA Dehydrogenase Deficiency

Multiple acyl-CoA dehydrogenase deficiency (MADD) is an inherited fatty acid oxidation disorder (FOD). A person with MADD cannot efficiently breakdown fats and protein into energy. Once the body uses up its first source of energy, blood sugar (glucose), the body becomes weaker because it cannot then make energy from fats. Therefore, people with this disorder must eat on a very regular basis and should not go long without food. The person presents variable body odor of sweaty feet.

e. Isovaleric Acidaemia

Isovaleric acidaemia is a rare genetic condition in which the body is unable to process certain proteins properly. People with this disorder have abnormal levels of an enzyme that helps break down the amino acid leucine, a building block of proteins. It is related to the genetic metabolic disorder Maple syrup syndrome. A symptom of isovaleric acidemia is a odor of cheesy, acrid,sweaty feet. This odor is result of the buildup of isovaleric acid compound.

f. Tyrosinaemia

Tyrosinaemia is an error of metabolism, inherited, in which the body can not effectively break down the amino acid tyrosine, found in most animal and plant proteins. It is an autosomal recessive, that means two copies of an abnormal gene must be present in order for this to develop. There are three types of tyrosinemia, each with distinctive symptoms and caused by the deficiency of a different enzyme. One of the symptoms of Tyrodinaemia type 1 is a odor like cabbage or rancid butter.

g. Diabetes Mellitus

Diabetes Mellitus. Almost all of the food we eat is broken down into glucose (sugar in the blood). Glucose is the main source of fuel for the body and is used by cells for growth and energy. Glucose needs insulin to get into cells. Insulin is a hormone made by the pancreas. In individuals with diabetes, the pancreas may create little or no insulin, or the cells do not react appropriately to the insulin that is produced. Glucose builds up in the blood, and is excreted in the urine. So the body loses its primary source of fuel. Fruity breath is present in people with diabetes.

h. Diabetic Ketoacidosis

Diabetic ketoacidosis. When the level of the blood sugar gets too high, the body creates "ketones" as a by-product of fat digestion. These ketones create blood acidity which causes "acidosis" of the blood. At the same time, the kidneys excrete large amounts of glucose-rich urine, causing dehydration. The patient may have a fruity breath, a sweet taste on the skin, or emanate a distinctive, chemical smell.

3-Methylcrotonylglycinuria, multiple carboxylase deficiency or 3MCC is another autosomal recessive genetic trait means that this faulty gene usually appears when two carriers have children together and pass it to their offspring. In this case the body is unable to process certain proteins properly. Patients have abnormal levels of an enzyme that helps break down proteins containing the building block (amino acid) called leucine. As a carboxylase enzyme, 3-MCC requires biotin for activity. There are four carboxylases in humans that use biotin and each can be deficient singly or together. If biotin metabolism is defective, functions of all four carboxylases will be low, resulting in Multiple Carboxylase Deficiency. MCC is predominantly located in the inner membrane of the mitochondria. The patient presents an odor like male cat urine.

Cystinuria is an inherited, metabolic disorder. It is characterized by the accumulation of cystine crystals (uroliths, caculi or stones) in the kidneys, ureter and bladder. People with cystinuria cannot properly reabsorb cystine into their bloodstream during the filtering process in the kidneys. Cystine is a amino acid, a building block of proteins. Most of the time, this excess cystine is simply excreted in the urine. But in some cases the cystine cannot stay dissolved and forms crystals. Because cystine is one of the sulfur-containing amino acids, the urine may have a characteristic "rotten egg" odor.

Hypermethioninemia this condition can happen when methionine (amino acid) is not metabolized correctly in the body. Individuals with this condition may experience a fishy, sweety and fruity, rancid butter or boiled cabbage odor. It has been said that tyrosinosis-tyrosinemia is the same as hypermethioninemia.

Oast-house syndrome also called Smith-Strang diesease is an inherited disease (autosomal recessive) due to malabsorption of methionine and secondary malabsorption of other amino acids. Part of the unabsorbed methionine is converted by colonic bacteria to a-hydroxybutyric acid. The urine has an odor similar to that of dried celery, yeast or malt, or an oasthouse (a building for drying hops). The patients have white hair, mental retardation among other symptoms.

Congenital adrenal hyperplasia – CAH is a group of inherited disorders which causes an enzyme deficiency (most commonly 21-hydroxylase) resulting in the inability of the adrenal glands to make hormones: cortisol and/or aldosterone. Since the body can't make enough cortisol (and in some cases aldosterone), it stimulates the production of other adrenal hormones that are called androgens. Three main forms of Congenital Adrenal Hyperplasia (CAH) exist: the severe salt-wasting, non-salt wasting forms, and a milder form. The non classical or milder form of CAH can produce body odor during childhood because of the premature puberty.