Frontal lobe disorder isn't always frontotemporal dementia... Right?

So, I was basically born with an underdeveloped left frontal lobe. From what I know, this can be referred to as frontal lobe disorder or frontal lobe syndrome (FLD). However, when I try to google things about it Google just keeps confusing it with bvFTD. I am almost 18, so I don't think I could have had FTD for all this time and still be alive. However, I can't really ask my mum about it since she would get a bit suspicious of me (not to mention this disorder was kept a secret from me for 16 years). It's really annoying since I can't find nay precise information on the disorder. Hope it's well understandable and allowed, if not, then please let me know! <3 Have a great day! (genuine intentions)