Most TBC1D24-related disorders are transmitted in an autosomal recessive manner. This means that two healthy parents each carry one good and one defective copy of the TBC1D24 gene. When they both pass on the defective copy to their child, he will develop a TBC1D24-related disorder.
It is thought that non-functional TBC1D24 protein causes TBC1D24-related disorders, but more research is needed to better understand how defective TBC1D24 protein can cause the different symptoms.
An extremely rare form of heritable hearing loss (DFNA65) is also caused by TBC1D24 and can be passed down from one generation to the next. This has only been seen in two families and currently no information is available as to how this autosomal dominant variant can cause deafness.