[Aquinasfan]

I was also taught that human beings are flawed (not "totally depraved," but flawed), because of a catastrophic error committed very near the beginning of the human race, the consequences of which are transmitted to every succeeding generation.

Yes. This corresponds with common experience. I like Fr. Groeschel's quip: "If you know someone who doesn't believe in original sin, tell him to come and visit me in New York."

I am not clear whether that means the consequences are "genetic," (yes? no?)

Analogously but mysteriously. It could be called a spiritual "genetic" defect. From the Catholic Encyclopedia entry on Original Sin:

Original sin may be taken to mean: (1) the sin that Adam committed; (2) a consequence of this first sin, the hereditary stain with which we are born on account of our origin or descent from Adam.

...but among the the practical consequences are that our intellects are darkened and our instincts somewhat deranged and hard for us to consciously control.

We all experience this inner turmoil and struggle, at least to some degree. But if you're not struggling, you're in pretty serious trouble.

[Elsie]

I was also taught that human beings are flawed (not "totally depraved," but flawed), because of a catastrophic error committed very near the beginning of the human race, the consequences of which are transmitted to every succeeding generation.

Genesis 3:6
When the woman saw that the fruit of the tree was good for food and pleasing to the eye, and also desirable for gaining wisdom, she took some and ate it. She also gave some to her husband, who was with her, and he ate it.

Yup!

Sure looks that way!