Is Darth Sidious a true Sith?

Now I know that he is called the Dark Lord of the Sith but there are many converts and fallen Jedi who claim to be Sith. But what I want to know is if he is offspring of those who had been apart of the Sith Alchemy and has the blood of the true race of the red skinned force using Sith of Korriban. I could not find any real references in Wookiepedia or anywhere else Im sure that the extended universe has the answer but I don't have the time to read all the books.