Are the bride's parents obliged to inform the suitor that their daughter carries the gene for the hereditary disease hemophilia?

The suitor must be informed of an illness if it is one that naturally causes aversion. As for ordinary illnesses that do not lead to aversion, there is no need to inform him of them. The fundamental principle is that the illness which must be disclosed to the suitor is one that establishes the option of annulment in marriage.