Ventral anterior homeobox 1 is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 that in humans is encoded by the VAX1 gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

.

Function

This gene appears to influence the development in humans of the forebrain. It is also present in mice and xenopus

Xenopus

Xenopus is a genus of highly aquatic frogs native to Sub-Saharan Africa. There are 19 species in the Xenopus genus...

 frogs, which suggests a long evolutionary history, and in those organisms its expression is confined to the forebrain, optic and olfactory areas.

VAX1 gene is a transcription factor that has a homeodomain

Homeodomain fold

The homeodomain fold is a protein structural domain that binds DNA or RNA and is thus commonly found in transcription factors. The fold consists of a 60-amino acid helix-turn-helix structure in which three alpha helices are connected by short loop regions...

 located in the 100-159 amino acid position and an Ala–rich region located in 216-253 amino acid position of the gene. Expression studies in mice show that it is expressed in the palate

Palate

The palate is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but, in most other tetrapods, the oral and nasal cavities are not truly separate. The palate is divided into two parts, the anterior...

, coloboma

Coloboma

A coloboma is a hole in one of the structures of the eye, such as the iris, retina, choroid or optic disc...

 in the visual system, and the basal telencephalon, optic stalk, and visual eye fields where it is expressed along with the Shh

Sonic hedgehog

Sonic hedgehog homolog is one of three proteins in the mammalian signaling pathway family called hedgehog, the others being desert hedgehog and Indian hedgehog . SHH is the best studied ligand of the hedgehog signaling pathway. It plays a key role in regulating vertebrate organogenesis, such as...

 and Bmp4

Bone morphogenetic protein 4

Bone morphogenetic protein 4 is a protein that in humans is encoded by` BMP4 gene.BMP4 is a member of the bone morphogenetic protein family which is part of the transforming growth factor-beta superfamily...

 genes.

Clinical significance

Mice with homozygous VAX1 mutations have been reported to display craniofacial malformations including cleft palate.

Genome Wide Association Studies (GWAS

Genome-wide association study

In genetic epidemiology, a genome-wide association study , also known as whole genome association study , is an examination of many common genetic variants in different individuals to see if any variant is associated with a trait...

) reported significant associations between non-syndromic clefts and SNPs in the VAX1 gene. Replication studies have confirmed these associations in different population groups

Further reading