DNAI1

The DNAI1 gene provides instructions for making a protein that is part of a group (complex) of proteins called dynein. This complex functions within cell structures called cilia. Cilia are microscopic, finger-like projections that stick out from the surface of cells. Coordinated back and forth movement of cilia can move the cell or the fluid surrounding the cell. Dynein produces the force needed for cilia to move.

Within the core of cilia (the axoneme), dynein complexes are part of structures known as inner dynein arms (IDAs) and outer dynein arms (ODAs) depending on their location. Coordinated movement of the dynein arms causes the entire axoneme to bend back and forth. IDAs and ODAs have different combinations of protein components (subunits) that are classified by weight as heavy, intermediate, or light chains. The DNAI1 gene provides instructions for making intermediate chain 1, which is found in ODAs. Other subunits are produced from different genes.

primary ciliary dyskinesia - caused by mutations in the DNAI1 gene

At least 20 mutations in the DNAI1 gene have been found to cause primary ciliary dyskinesia. These mutations result in an absent or abnormal intermediate chain 1. Without a normal version of this subunit, the ODAs cannot form properly and may be shortened or absent. As a result, cilia cannot produce the force needed to bend back and forth. Defective cilia are responsible for the features of primary ciliary dyskinesia, including respiratory tract infections, abnormal organ placement, and an inability to have children (infertility).