GLI3 gene
The GLI3 gene acts as a transcription factor that regulates gene expression, playing a vital role in the early development and patterning of tissues and organs.
Overview
The GLI3 gene belongs to a family of genes involved in the early development of many tissues and organs. Proteins produced by this gene act as transcription factors, attaching to specific regions of DNA to control whether other genes are turned on or off.
The GLI3 protein functions within the Sonic Hedgehog signaling pathway, which is essential for cell growth, specialization, and the patterning of structures such as the brain and limbs. Depending on the signals received, GLI3 can either activate or repress target genes.
Health Conditions Related to Genetic Changes
Acrocallosal syndrome
Mutations in the GLI3 gene can cause acrocallosal syndrome, a rare condition characterized by:
- Brain abnormalities
- Extra fingers and toes (polydactyly)
- Distinctive facial features, including widely spaced eyes (hypertelorism) and a prominent forehead
Greig cephalopolysyndactyly syndrome
This condition is caused by genetic changes that prevent one copy of the GLI3 gene from producing functional protein, resulting in a reduced amount of GLI3 available during development. Features include:
- Polydactyly
- Hypertelorism
- Broad forehead
- Unusually large head (macrocephaly)
Pallister-Hall syndrome
Mutations near the middle of the gene often create a premature stop signal, leading to the production of an unusually short version of the GLI3 protein. This short protein can only repress target genes. Major features include:
- Polydactyly
- Hypothalamic hamartoma (an abnormal growth in the brain)
- Bifid epiglottis (a malformation of the airway)
Other disorders
GLI3 mutations can also cause isolated or nonsyndromic polydactyly, where extra digits occur without other systemic features. These include:
- Postaxial polydactyly type A (PAP-A) and type A/B (PAP-A/B): Extra digits next to the little finger or small toe.
- Preaxial polydactyly type IV (PPD-IV): Extra digits next to the thumb or big toe, often accompanied by fused skin (cutaneous syndactyly).
Other Names for This Gene
- ACLS
- GCPS
- GLI-Kruppel family member GLI3 (Greig cephalopolysyndactyly syndrome)
- GLI3_HUMAN
- oncogene GLI3
- PAP-A
- PAPA
- PAPA1
- PAPB
- PHS
- PPDIV
- zinc finger protein GLI3
