Anavex Life Sciences Corp (AVXL)

[falconer66a]

No Genetic Correction, But Possible Moderation

Is it your understanding that 2-73 can be used in pregnancy to correct chromosome X to prevent rare diseases like Fragile X syndrome and others that occur?

Good question: could Anavex 2-73 (blarcamesine) be used to prevent the expression (working) of pathogenic genes, as in the case with Fragile X?

I don’t know. Fragile X is sex-linked, meaning that the pathogenic gene (FMR1) is located on the X chromosome. An individual with two X chromosomes, one inherited from the mother, the other from the father, is a female. Males have a single X chromosome, inherited from the mother (she can only donate X chromosomes, she has two). The other sex-determining chromosome is the Y, inherited from the father. It is the random selecting of the father’s sex chromosomes, X or Y, that determines the sex of the child, at conception.

Hence, the predominance of Fragile X syndrome in boys. They have only one X, from the mother. If it’s one with the FMR1 gene, the boy will have Fragile X. In the case of girls, two X chromosomes. If either one of them has the bad gene, the disease is expressed, occurs.

When the FMR1 disease-causing gene is present, could Anavex 2-73 keep it from being expressed, preventing the onset of its symptoms? I don’t know. Seems unlikely.

But, as the early clinical trials show, the drug may well be able to moderate the severity of the untoward symptoms; making the disease less severe. Let’s see how this works out in humans with the disease.

It was asked if the drug could be used “in pregnancy” to correct the chromosome X genetic defect. Too late. The mutation, creating the bad gene, happens long before pregnancy; sometime during or even long before spermatogenesis (sperm formation). But, there, the Anavex drugs may suppress bad mutations, making eggs and sperm genetically “pure,” without bad mutations. If that’s the case, dosing with Anavex drugs would have to be early, particularly in females. Actually, genetic oogenesis, egg formation, actually occurs very early, even before birth. So a woman would have had to take blarcamesine while she was yet in utero. Well, her mother would have had to take it.