The FGF3 protein is a member of the fibroblast growth factor (FGF) family that are required for important processes such as cell division, regulation of cell growth and maturation, formation of blood vessels, wound healing, and development before birth. FGF3 is also involved in the development of many organs and structures, including the outer ears and teeth. These proteins are able to elicit different cellular responses dependent on ligand/receptor combination and embryonic environment. The loss of FGF3 function impairs development of the inner ear structures and teeth, which leads to the characteristic features of LAMM syndrome.

The gene encoding for Fibroblast Growth Factor 3 is located on chromosome 11 and consists of three coding exons. The gene spans a length of about 9.5 Kb, while the FGF3 protein is made of 239 amino acids.

Mutations in the FGF3 gene are the cause of a unique autosomal recessive syndrome called deafness with labyrinthine aplasia, microtia and microdontia (LAMM). These mutations have variable expressivity with manifestations ranging from fully penetrant LAMM to deafness with residual inner ear structures and minimal syndromic features.