I have found a couple of named races in my own investigations from previous editions, but nothing from 5e.
As far as I know these races have not been included in anything 5e-related, and the only official source for these races seem to come from a Dragon magazine for 3e, which I don't have, hence this information is only what I can find online from Wikipedia or Forgotten Realms Wiki.
But for what it's worth, here's what I found (maybe someone with that magazine could edit this/submit their own answer with better information; it's still not 5e related, but it's something that someone could homebrew, at least).
D'hin'ni
The d'hin (1, 2) are a race of half-lightfoot halflings and half-djinni (air elemental genies).
A d'hin'ni was a type of planetouched that was the combination of a genie ancestor and halfling (or hin as they were also called) blood.
Commonly descended from slave lightfoot hin and their djinn masters, they mixed the halfling's disinterest in the battles of morals and ethics, but the unpredictibility of djinn caused the majority of them to take the chaotic neutral alignment. (from Forgotten Realms Wiki)
Azerblood
The azerblood (1) are a race of half-mountain dwarves and half-azer (fire elementals, though not genies).
An azerblood is a type of planetouched that is the combination of a fire outsider known as an azer and dwarven blood [...]
Azerblood resemble a dwarf of the shield dwarf subrace for the most part, with some variations based on the outsider blood that flows in their veins[citation needed]. Common traits are metallic brass-coloured skin, flame-red hair and irises that appear to move with flames. (from Wikipedia)