What causes TRAPPC6B-related syndrome at the molecular level?
Inside every cell, there are tiny machines that move important materials from one place to another like a postal system for the cell. The TRAPPC6Bgene makes a part of one of these machines, called the TRAPP complex. This machine helps move materials from where they are made to where they need to go inside the cell. When the TRAPPC6Bgene has changes (mutations) in both copies, this cellular postal system does not work properly. As a result, the brain does not develop normally, leading to the symptoms seen in this condition.
What type of genetic change causes this condition?
Most affected individuals have changes in both copies of the TRAPPC6Bgene that stop the gene from working (called loss-of-function mutations). A specific genetic change (c.82-2A>G) was first discovered in Egyptian families and appears to be relatively more common in Egyptian individuals.
How is the diagnosis made?
The diagnosis is confirmed by genetic testing, usually through a blood test that analyses the TRAPPC6Bgene (gene panel or whole exome sequencing). Once a mutation is found in an affected child, both parents should be tested to confirm they are carriers.
TRAPPC6B