SACK1H gene
The SACK1H gene provides instructions for a protein that maintains cell structure and is critical for the formation of tooth enamel.
Normal Function
The SACK1H gene produces a protein found in cells throughout the body. This protein interacts with others in the cytoplasm to help maintain the cytoskeleton, which provides structural support to the cell.
High levels of the SACK1H protein are found in ameloblasts, specialized cells responsible for producing tooth enamel—the hard, protective outer layer of the teeth. In these cells, the protein plays a key role in regulating the processes required for enamel formation.
Health Conditions Related to Genetic Changes
Amelogenesis imperfecta
Variants in the SACK1H gene can cause amelogenesis imperfecta, a disorder where tooth enamel does not form properly. This results in teeth that may be unusually small, discolored, pitted, or grooved. When caused by SACK1H variants, the condition is inherited in an autosomal dominant pattern.
- Most variants introduce a premature stop signal, leading to the production of an abnormally short version of the SACK1H protein.
- While normal SACK1H is found in the cytoplasm, this shortened version accumulates in the cell's nucleus.
- The altered protein traps other essential proteins within the nucleus, preventing them from performing their functions in the cytoplasm.
- These "dominant-negative variants" disrupt the structure of ameloblasts, leading to the weak, fragile, and discolored enamel characteristic of the disorder.