It is possible to have LQTS and be asymptomatic while others (with the same gene) might experience severe symptoms. To answer your question - yes, a person can reach age 45 with LQTS and not have any major complications.
If your have reason to suspect that you have LQTS, then you should contact SADS and find an EP who specializes in the syndrome to see you. LQTS is not always detected on a resting EKG and only one of the forms of LQTS is detected using a stress test - this is why it is important to see a specialist if you suspect you might have it
But surely if you have it then u wouldn't just show symptoms like seizures in your childhood and suddenly grow out of it?
And itdood I apologise I think u have the wrong end of the spectrum. I haven't been diagnosed with it and have had normal tests in the past, nobody in my family has it, just the seizure business I recently found out about has turned me detective lol.
My point I was trying to grasp was, if my relative who had seizures when she was a child DID have long qt syndrome, wouldnt she of had some sort of complications before the age 45! Considering this syndrome is triggered by unavoidable things that us humans do like exercise and waking to alarms for work etc.
That's a rather complex family history you're talking about. I'm not even sure a specialist in the field could give you a conclusive answer as to what the future might hold. If I were you I would definitely keep a close eye on it given your family and personal history. I would speak with a doctor about limitations on your physical activity. I've read about how there is a correlation between long QTc and seizures in children but that doesn't mean one causes the other. I think the theory is that whatever chemical issue causes seizures also can prolong QT interval. But I've also read it implies the possibility of an arrhythmic origin of some seizures. Scary stuff I'm sure.
A friend of mine has familial long QTc. A lot of scary stuff going on his family. It skipped him, he's now approaching 50 and no signs of it for him, but his daughter just started to show symptoms. It's something you have to be aware of and manage with your healthcare professionals.