Failure of the tricuspid valve to close sufficiently upon contraction of the right ventricle, causing blood to regurgitate (flow backward) into the right atrium.

Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm.

Impairment of bile flow due to obstruction in bile ducts.

Abnormally increased size of the liver.

A chronic disorder of the liver in which liver tissue becomes scarred and is partially replaced by regenerative nodules and fibrotic tissue resulting in loss of liver function.

The presence of excessive fibrous connective tissue in the liver. Fibrosis is a reparative or reactive process.

Impaired function of the exocrine pancreas associated with a reduced ability to digest foods because of lack of digestive enzymes.

The presence of chronic diarrhea, which is usually taken to mean diarrhea that has persisted for over 4 weeks.

Neonatal jaundice refers to a yellowing of the skin and other tissues of a newborn infant as a result of increased concentrations of bilirubin in the blood. Neonatal jaundice affects over half of all newborns to some extent in the first week of life. Prolonged neonatal jaundice is said to be present if the jaundice persists for longer than 14 days in term infants and 21 days in preterm infants.

Steatosis is a term used to denote lipid accumulation within hepatocytes.

Hepatic fibrosis that reaches from a portal area to another portal area.

A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve.

Mild intellectual disability is defined as an intelligence quotient (IQ) in the range of 50-69.

A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.

An extra-parenchymal and intra-arachnoidal collection of fluid with a composition similar to that of cerebrospinal fluid.

A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.

A reduction in the number of circulating thrombocytes.

A kind of anemia in which the volume of the red blood cells is normal.

Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.

The capability that a joint (or a group of joints) has to move, passively and/or actively, beyond normal limits along physiological axes.

An abnormal decreased number of leukocytes in the blood.

Abnormal increased size of the spleen.

An abnormally decreased level of immunoglobulin M (IgM) in blood.

Increased susceptibility to infections.

An accessory spleen is a round, iso-echogenic, homogenic and smooth structure and is seen as a normal variant mostly on the medial contour of the spleen, near the hilus or around the lower pole. This has no pathogenic relevance.

Increased susceptibility to bacterial infections, as manifested by recurrent episodes of bacterial infection.

Undetectable serum immunoglobulin A level at a value < 5 mg/dL (0.05 g/L).

An abnormally decreased level of immunoglobulin in blood.

A reduction beneath the normal level of total immunoglobulin G (IgG) in the blood.

A lasting reduction beneath the normal level of total immunoglobulin G (IgG) in the blood.

An increased concentration of cholesterol in the blood.

The concentration of aspartate aminotransferase (AST) in the blood circulation is above the upper limit of normal.

An abnormally high concentration in the circulation of alanine aminotransferase (ALT).

A reduced concentration of copper in the blood.

Elevations of the levels of SGOT and SGPT in the serum. SGOT (serum glutamic oxaloacetic transaminase) and SGPT (serum glutamic pyruvic transaminase) are transaminases primarily found in the liver and heart and are released into the bloodstream as the result of liver or heart damage. SGOT and SGPT are used clinically mainly as markers of liver damage.

Abnormal transferrin isoform profile consistent with a type II congenital disorder of glycosylation.

An anomaly of protein O-linked glycosylation, i.e., of the process in which a carbohydrate or carbohydrate derivative unit is added to a protein via the hydroxyl group of a serine or threonine residue.

An anomaly of protein N-linked glycosylation, i.e., an abnormality of the protein glycosylation process in which a carbohydrate or carbohydrate derivative unit is added to a protein via a nitrogen atom in an amino acid residue in a protein.

An abnormally increased height of the forehead.

Wrinkled, redundant, inelastic and sagging skin.

An abnormality of refraction characterized by the ability to see objects in the distance clearly, while objects nearby appear blurry.

Interpupillary distance less than 2 SD below the mean (alternatively, the appearance of an decreased interpupillary distance or closely spaced eyes).