LARS2 is a protein which works in the mitochondria, the part of the cell which generates energy. If there is a mistake in the LARS2 protein this can interfere with the cells’ ability to generate energy. A gene is a section of DNA which contains the instructions to make a protein and changes in some of the letters in a gene can cause changes to the protein.
Perrault syndrome
This condition is caused by small changes to the gene which are the equivalent to changing a word in a sentence. Although the change is small changing one word in a sentence can change the meaning. These changes can make a protein work less efficiently.Some of these patients have a small change inherited from one parent with a deletion inherited from the second parent Deleting a section of a gene is the equivalent of deleting a section of a sentence so it no longer makes sense. These changes often mean the protein does not work.
LARS2 associated lethal infantile multisystem failure
This condition is caused by similar changes to those which cause Perrault syndrome but they affect the protein more severely. This means the LARS2 protein works less efficiently than both the unaltered protein and the protein with changes which cause Perrault syndrome.
Diagnostic testing
To test for mistakes in the protein LARS2 a doctor will look for changes in the LARS2 gene. As conditions caused by changes in LARS2 can be very similar to conditions caused by other genes your doctor will probably test a number of genes for changes at the same time. As someone affected by these conditions inherits an altered gene from each parent it can be useful to test the parents too.