Table 1.

Sample sizes of concordant pairs, discordant pairs, and singletons by zygosity for each dementia phenotype

All Dementia	MZ Male	DZ Male	MZ Female	DZ Female	DZ Opposite-Sex
	42	50	119	179	100
	80	147	115	270	306
	163	305	262	591	446
	354	775	437	848	1194
AD Only	MZ Male	DZ Male	MZ Female	DZ Female	DZ Opposite-Sex
	17	22	59	74	32
	35	76	62	155	160
	120	187	213	458	304
	399	846	490	963	1340
Non-AD Dementia	MZ Male	DZ Male	MZ Female	DZ Female	DZ Opposite-Sex
	7	11	10	26	18
	40	71	53	115	146
	79	152	149	291	242
	389	851	499	1003	1354
Pairs w/No Dementia Diagnosis	302	461	430	620	871
Totals	MZ Male	DZ Male	MZ Female	DZ Female	DZ Opposite-Sex
Any Dementia	941	1738	1363	2508	2917
AD Only	873	1592	1254	2270	2707
Non-AD Dementia	822	1546	1141	2055	2631

Note. Concordant pairs are pairs where both twins are cases (i.e., diagnosed with dementia; discordant pairs are pairs where one twin is a case and the co-twin is a control; Singletons (case and control) comprise information on one twin where the co-twin is missing.