Inherited Disease or Conditions That Would Cause Low HT?

[Icelander]

I'm randomly generating backstory for numerous related characters and I note that despite having decent to good physical Attributes otherwise, active lives and careers, outdoorsy hobbies and so forth, most of them have HT below average and some of them have HT so low it would represent some serious medical issue, almost totally immunocompromised.

For one or two, it could be a coincidence, but when the third character in two generations of direct male descent has to medically retire due to HT so low that any ordinary flu might be fatal, to say nothing of infections, then I begin to wonder if there isn't some inheritable trait that would cause life-threatening illness at some point between puberty and middle-age, after which the immune system was trashed, cardiovascular system a mess, etc.?

Should mostly affect HT, they can have decent ST, DX, IQ, Per and Will, though, obviously, if they fall ill due to poor HT, all those other traits can take a hit too and Disdvantages start to appear. But the main lasting impact should be sharply reduced HT from what would otherwise be expected for their age and lifestyle.

[Donny Brook]

Asthma, congenital heart disease or deformities, hemophilia, vitamin absorption problems all come to mind.

[Anthony]

I'd look through a list of degenerative diseases.

[Icelander]

Originally Posted by Donny Brook

Asthma, congenital heart disease or deformities, hemophilia, vitamin absorption problems all come to mind.

I'm not sure how any of these might allow for decent ST and DX into young adulthood, if not longer, except congenital heart disease. It would have to be something that only became evident after puberty and, ideally, not until the 40s for one character. So, congenital heart disease that only manifests later in life or under conditions of stress might suit.

My first thought was maybe something auto-immune. Some auto-imune diseases or conditions have clear correlation by family history and often only manifest in adulthood, so a character could be an athlete, a soldier, a cop or any active job, at least until they experience symptoms for the first time.

Not that yours truly was much of an athlete after age thirteen or so, but I was mostly in rude physical health (apart from such GURPS-ian aspects as crippled limbs which never recovered fully) until I turned forty, at which time most systems in the body began failing like I was an electronic device made in a China with planned obsolesence. Granted, my symptoms don't include being immunocompromised, but I'm sure some auto-immune diseases mess up the actual immune system, rather than, e.g. leaving widespread nerve damage (which is lowered ST and DX, while I'm looking for lowered HT as the main effect).

There have to be some conditions or diseases which have inheritable characteristics, but only manifest at some time after puberty, in some cases perhaps not until the 30s or 40s, and primarily cause low HT. It's okay if some other traits are also lowered, especially if that's a consequence of being very sick and something which can be regained with therapy, but HT should be reduced permanently or at least for years and years.

Basically, looking for a medical justification for low GURPS HT, while ST and DX are good, or at least were while the character was young. Are there diseases which cause asthma-like symptom or versions of asthma that only manifest after a character has had an episode of serious illness in adulthood? And which depend on inheritable characteristics, like maybe a heart defect?

Or are there inheritable traits that make even modern people subject to recurrent tubercolosis or similar symptoms?

[Icelander]

Originally Posted by Anthony

I'd look through a list of degenerative diseases.

Of those, Felty's Syndrome with splenomegaly, anemia and perhaps lung involvement sounds promising. It usually presents with rheumatoid arthritis, but perhaps the lowered DX and ST can be managed better than the splenomegaly and other secondary symptoms.

[malloyd]

Depending on your setting there's always Divine Curse (Cursed with [ill-health/to die young], unto the [10-x]th generation).

[Rupert]

Originally Posted by Icelander

There have to be some conditions or diseases which have inheritable characteristics, but only manifest at some time after puberty, in some cases perhaps not until the 30s or 40s, and primarily cause low HT. It's okay if some other traits are also lowered, especially if that's a consequence of being very sick and something which can be regained with therapy, but HT should be reduced permanently or at least for years and years.

Basically, looking for a medical justification for low GURPS HT, while ST and DX are good, or at least were while the character was young. Are there diseases which cause asthma-like symptom or versions of asthma that only manifest after a character has had an episode of serious illness in adulthood? And which depend on inheritable characteristics, like maybe a heart defect?

Cruddy heart valves can appear fine for many years and then start failing simply because they're wearing out faster than a normal person's would. Poor valves can be caused by childhood illnesses (rheumatic fever, for example), but are also inheritable.

Similarly, having narrow heart arteries is inheritable (not blocked up, just naturally narrower than normal), and this generally doesn't cause any trouble until you start ageing and they start becoming stiff and blocked, and then the lack of capacity becomes an issue. Depending on how narrow they are, and how unhealthy the person's lifestyle (especially diet) is, the onset of this can be quite early or so late they died of something else first. Until the blood supply become poor enough to cause angina the person may not even really notice anything - they just don't have as much energy as they had when younger, get tired faster, recover more slowly, etc.

Until CABG operations became a thing in the 60s, there was no cure for heart disease caused by the vessels becoming constricted or blocked, so all you could do was 'take it easy' and be mindful of symptoms you were over-doing it.

[TGLS]

Maybe they passed poor diet decisions on to their children.

[johndallman]

Heart arrhythmia can be inherited, and bouts of arrhythmia can become much more common in an individual after catching an infectious disease. Personal experience: I was having one bout a year until I got Covid, then they happened weekly. Medication made me very woozy and would have forced me to retire in the past. I got it fixed with methods that weren't created until the 1980s, and didn't become routine until this century.

There are lots of arrhythmia conditions, so unless your players include a cardiologist, there seems no need to be specific.

[WingedKagouti]

There's also the option of Autoimmune Diseases, which are technically the other way around (ie the immune system is too agressive and attacks the body), but they can leave the body in a weakened state and are often inherited.

The most well known would be Type 1 Diabetes, but that was usually fatal at a young age prior to insulin being discovered.