While reading the Wikipedia
page of João Maria of Orléans-Braganza and his Egyptian princess wife
Fatma Sherifa Ismail Hussein Chirine (1923 - 1990) , cousin-in-law of Princess Fawiza of Egypt and Queen of Iran, I saw on the footnotes reference # 7 a link to this fascinating article where, in 2013 there was a genetic genealogy study done with the Brazilian branch of the Frenc Bourbons. It was to identify the true Y haplogroup of House of Bourbon of remains found of previous French kings, like blood samples from Louis XVII and the first Bourbon king, Henri.
In summary: The present members of House Orleans and House Borbon DNA descend from the historical Bourbons
Genetic genealogy reveals true Y haplogroup of House of Bourbon contradicting recent identification of the presumed remains of two French Kings
Here is the DNA family tree;
Figure - PMC
The presumed
head of Henri IV (1553-1610) paraded during the Frenc Revolution did not match the family and for this they studied the DNA of King Henri's maternal ancestor
Anna of Habsburg, (1280-1327):
Finally, the mitochondrial DNA analysis of the head also did not support the attribution of the sample to Henri IV. According to Charlier et al,24 the donor of the head belongs to mtDNA haplogroup U5b*. Our previous study of a series of living and deceased maternally related relatives of Louis XVII showed that the mtDNA haplogroup of the Habsburgs belonged to haplogroup H.4, 5
If the head sample was indeed attributed to Henri IV, this would mean that a non-maternity event happened somewhere between Henri IV and Marie-Antoinette, an event which is known to occur very exceptionally but without any indication in written records
Lesson here, you never know what would you find when researching royal history of past and present royals discussed here in the Royal Forums.
Always look out for those Wikipedia references foot notes! 
