TAT Gene

The TAT gene (TAT is the acronym for tyrosine aminotransferase) is located on chromosome 16q22.2 and encodes a mitochondrial protein, tyrosine aminotransferase, an enzyme found in the liver that catalyzes the conversion of L-tyrosine to p-hydroxyphenylpyruvate. Mutations in this gene cause tyrosinemia (type II, Richner-Hanhart syndrome), a disorder associated with palmoplantar keratosis and corneal lesions, possibly leading to cognitive impairment. TAT (tyrosine aminotransferase) is a protein-coding gene located on chromosome 16q22.2.

Diseases associated with TAT include:

Tyrosinemia, type II

The encoded protein is an enzyme, transaminase, which is involved in tyrosine degradation. The enzyme converts tyrosine to p-hydroxyphenylpyruvate. Furthermore, it can catalyze the reverse reaction in vitro using glutamic acid with 2-oxoglutarate as a cosubstrate. Has much lower affinity and transaminase activity towards phenylalanine.

Tyrosinemia type 2 (OMIM: 276600) is a genetic disorder (deficiency of the enzyme tyrosine aminotransferase) in which the amino acid tyrosine, tyrosine is a building block involved in most proteins, is present in elevated concentrations in the blood of affected individuals. Symptoms of tyrosinemia type 2 often begin in early childhood and include excessive tearing, abnormal sensitivity to light (photophobia), eye pain and redness, and painful palmoplantar hyperkeratosis . About 50 percent of those affected have mental retardation.

1. Maydan Get al. (2006) TAT gene mutation analysis in three Palestinian kindreds with oculocutaneous tyrosinaemia type II; characterization of a silent exonic transversion that causes complete missplicing by exon 11 skipping. J Inherit Metab Dis 29:620-626.