What does it mean if you have an x-linked recessive gene mutation?
Answer from: Maria José Mendiola, MD, MSc in Human Genetics, MSc in Science Communication, ObGyn
Clínica Monterrico
Variants on the x chromosome are most often recessive. Some cases they could be dominant but in most cases they are recessive so, this means that if there is a working copy of the same gene, in each cell of a person, they will not usually show symptoms of the condition. In other words, the working copy of the gene is a backup for the other non-working copy of the gene. We have two copies and, for example, we have a girl, a female that has two copies of a gene because they are two X chromosomes: one of the X chromosomes has a recessive variant and the other has a working copy of the gene. In this case, this person is a genetic carrier and although only one of the gene copies is sending the right instructions to make the gene product, it can usually work with this. In many x-linked recessive conditions, females who carry a gene variant will not have any symptoms of the conditions. Some conditions however may affect females who are genetic carriers and this is thought to be to the X inactivation process that switches off the x with the working gene and more body cells so, the working copy of the x chromosome is not switched on enough to protect this person from developing the conditions. Males who have in this case the recessive gene variant on their x chromosome do not have a second chromosome with a working copy of the gene – they do not have a backup therefore, a they will not able to send the right message to the cells to make the gene product and they will have the condition.
What does it mean if you have an x-linked recessive gene mutation?
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