There's Sid Ceasar, and Ceasar Romero. But seriously.
Its doubtless that there are many living descendants of Roman Emporers around today.
But actually tracing and documenting the linneage a living person back to a roman emperorer would be difficult.
But in china there are supposidley people around today who can trace their lineage back to Confucius, who lived in around 500 BC ( before the greeks built the Parthenon in 432 BC) which was centuries before Rome started to have Emporer.s So I guess it might not be impossible.
When the republican government of early rome gave way to them having emperors( a little before christ)- they then had an unbroken chain of emporers until the last western emperors was overthrown by the barbarians in AD 476.
The Eastern Empire (centered in Byzantium) continued for another thousand years until the last remnant was destroyed by the Ottoman Turks in 1453 AD- but the eastern emperors after 476 AD are considered 'Byzantine' rather than 'roman'. But that means you still have 500 years of western (truly 'roman') emporers to pick from.