Haplogroup H (mtDNA)
In human mitochondrial genetics, Haplogroup H is a human mitochondrial DNA (mtDNA) haplogroup.
The Cambridge Reference Sequence (CRS), the human mitochondrial sequence to which all other sequences are compared, belongs to haplogroup H.
About one half of Europeans are of mt-DNA haplogroup H. The haplogroup is also common in North Africa and the Middle East.  According to FamilyTreeDNA , currently the largest genetic genealogy testing firm, approximately 32% of the their database is haplogroup H. Of those H results, approximately 21% of them has a 519C mutation, which is volatile and generally not useful in characterizing subclades. The 4336 tRNA nucleotide position variant in haplogroup H has been shown to be associated with late-onset Alzheimer's disease.
In his popular book The Seven Daughters of Eve, Bryan Sykes named the originator of this mtDNA haplogroup Helena.

# Relationship to other haplogroups
Haplogroup H is a descendant of haplogroup HV.
- Haplogroup L1
Haplogroup L3
Haplogroup N
Haplogroup R
Haplogroup U
Haplogroup pre-HV
Haplogroup HV
Haplogroup H
- Haplogroup L3
Haplogroup N
Haplogroup R
Haplogroup U
Haplogroup pre-HV
Haplogroup HV
Haplogroup H
- Haplogroup N
Haplogroup R
Haplogroup U
Haplogroup pre-HV
Haplogroup HV
Haplogroup H
- Haplogroup R
Haplogroup U
Haplogroup pre-HV
Haplogroup HV
Haplogroup H
- Haplogroup U
Haplogroup pre-HV
Haplogroup HV
Haplogroup H
- Haplogroup pre-HV
Haplogroup HV
Haplogroup H
- Haplogroup HV
Haplogroup H
- Haplogroup H

## Subclades
Haplogroup H is divided into various subclades.
- Haplogroup H
H4
H4a
H14
H5
H5a
H5a1
H6
H6a
H6a1
H6b
H6c
H8
H11
H15
H2
H2a
H2a1
H2b
H2c
H7
H9
H10
H1
H1a
H1b
H3
H12
H13
- H4
H4a
- H4a
- H14
- H5
H5a
H5a1
- H5a
H5a1
- H5a1
- H6
H6a
H6a1
H6b
H6c
- H6a
H6a1
- H6a1
- H6b
- H6c
- H8
- H11
- H15
- H2
H2a
H2a1
H2b
H2c
- H2a
H2a1
- H2a1
- H2b
- H2c
- H7
- H9
- H10
- H1
H1a
H1b
- H1a
- H1b
- H3
- H12
- H13

# People in haplogroup H
(Note: The below list is an incredibly tiny and unrepresentative sampling, as nearly 1 of 2 Europeans share this haplogroup)

## Marie Antoinette
Marie Antoinette, and her matrilineal ancestors back to Bertha von Putelendorf (died 1190), were of haplogroup H.  (Jehaes et al, European Journal of Human Genetics, vol 6, pp. 383-395 (1998) and vol 9, pp. 185-190, (2001): the extended sequence is: HVR1 T16519C; HVR2 T152C, C194T, A263G and N315.1C.)  If all pedigrees are assumed correct, the following other matrilineal relatives of Marie Antoinette were of haplogroup H: Maria Theresa of Austria, Marie-Louise of Austria (second wife of Napoleon Bonaparte), Peter II of Russia, Pedro II of Brazil, Philip III, Duke of Burgundy, Leopold II of Belgium, Frederick William II of Prussia, Ferdinand I of Bulgaria, Victor Emmanuel II of Italy, August III the Saxon, and Stanisaw August Poniatowski.  

## Empress Alexandra Fyodorovna
Among other famous members of group H are Empress Alexandra Fyodorovna, wife of the last Russian tsar Nicholas II, and all of her children.  Their membership in haplogroup H was established when genetic testing was done on their remains to authenticate their identity.
As a consequence, all of relatives on the matrilineal line also have this haplogroup.  These include Alexandra Fyodorovna's relatives along the matrilineal line all the way back to her ancestor Blanca Nunez de Lara (approx. 1317  1347), which include her grandmother Queen Victoria and her cousins the Duke of Edinburgh, Lord Mountbatten, and Wilhelm II of Germany and his wife Augusta Viktoria of Schleswig-Holstein.  Other matrilineal descendants of Blanca Nunez de Lara include Marie de' Medici, Anne of Austria, Charles II, James II, and William III of England, Leopold I of Belgium, Wladislaus IV and John II of Poland, Michael I of Romania, George II, Alexander I, Paul and Constantine II of Greece, Christian VI of Denmark, Louis XIII, Louis XV and Louis XIV of France, Charles XI, and Christina of Sweden, William I of the Netherlands, Philip V, Philip IV, and Charles II of Spain and Queen Sophia of Spain. .

## Others
In a BBC Wales program about her father's Welsh ancestry, Susan Sarandon was revealed to be of haplogroup H.