Table 1.

Distribution of mtDNA C150T homoplasmic transition in leukocytes from an Italian population

	Overall sample donors		G samples		L-M samples
	n	C150T (%)*	n	C150T (%)*	n	C150T (%)*
Centenarians,† 99–106 y	52	9 (17.3)	43	7 (16.2)	36	7 (19.4)
Controls,‡	117	4 (3.4)	76	2 (2.6)	76	2 (2.6)
18–98 y	P = 0.0035		P = 0.0107		P = 0.0048

	Monozygotic		Dizygotic
	n	C150T (%)	n	C150T (%)
Twins, 60–75 y	20	6 (30)	18	4 (22)
Controls,	117	4 (3.4)	117	4 (3.4)
18–98 y	P = 0.0007		P = 0.0113

 G, granulocytes; L-M, lympho-monocytes. The P values for the difference in frequency of the C150T homoplasmic transition between centenarians and controls and between monozygotic or dizygotic twins and controls were calculated by Fisher's exact test. 

^*The numbers and percentages shown represent the absolute and relative frequencies of the C150T homoplasmic transition. 

^† These include 43 donors of G and/or L-M samples and donors of buffy coats. 

^‡ These include 78 donors of G and/or L-M samples and 39 donors of buffy coats. The apparent discrepancy between the number of overall G and L-M sample donors (78) and the number of G samples and L-M samples is due to the fact that, for a few of the donors, only the G sample or the L-M sample was available (74 shared donors).