Table 2: Mitochondrial variation/haplogroups associated with AD.

HaplogroupDatasetEffectEthnicityNo. cases/controls

B4C1 [132]Selected SNPsRiskJapanese96/384
G2A [132]Selected SNPsRiskJapanese96/384
HV [133]Haplogroups, SNPsRiskPolish222/252
H [134]HVS-I sequenceRiskIranian30/100
H5/H5A [135]D-loop sequence, restriction analysisRiskItalian936/776
H6A1A/H6A1B [136]Full mtDNA sequencesProtectiveCaucasian101/632
K [137]HaplogroupsProtectiveItalianN/A*
N9B1 [132]Selected SNPsRiskJapanese96/384
U [134, 138]HVS-I sequence, 10 SNPsRiskIranian, Caucasian30/100, 989/328**
U [137, 138]Haplogroups, 10 SNPsProtectiveItalian, CaucasianN/A*, 989/328**
UK [139]138 SNPsRiskCaucasian170/188
None [140]4 SNPsNoneUnknown70/80
None [141]European haplogroupsNoneUnknown185/179
None [142]U, K, J, and T haplogroupsNoneEnglish185/447
None [143]European haplogroupsNoneTuscan209/191
None [144]HaplogroupsNoneFinnish128/99***
None [145]138 SNPsNoneCaucasian3250/1221

The authors showed that haplogroups U and K neutralized the risk of the APOE e4 allele.
The authors demonstrated an increased risk for AD for males with haplogroup U and decreased risk for females with haplogroup U.
These were early onset AD cases.