Table 2 The probandwise concordance rates in monozygotic (MZ) and same gender dizygotic (DZ) twin pairs with migraine without aura, migraine with aura and tension-type headache without co-occurrence of migraine. The concordance rates are in percentage and the 95% confidence intervals are in parenthesis. n.s. denotes not significant

Migraine without aura

Gervil et al. [19]

29 (3–55)

15 (‒19 to 49)

50 (41–59)

37 (31–43)

43 (37–49)

31 (26–36)

Migraine with aura

Ulrich et al. [18]

53 (35–71)

29 (15–43)

48 (32–64)

15 (4–26)

50 (38–62)

21 (12–30)

Tension-type headache No

Russell et al. [22]

50 (43–57)

40 (33–48)

51 (40–62)

33 (20–46)

50 (45–56)

38 (32–45)

p-values

<0.001

<0.001

<0.001

Infrequent episodic

Russell et al. [22]

75 (73–78)

74 (71–76)

78 (76–81)

71 (68–74)

77 (75–79)

73 (71–74)

p-values

n.s.

<0.001

<0.001

Frequent episodic

Russell et al. [22]

34 (21–48)

18 (2–34)

50 (43–57)

37 (29–45)

46 (39–52)

32 (25–39)

p-values

<0.001

<0.001

<0.001

Chronic

Russell et al. [22]

0 (‒)

0 (‒)

15 (‒52 to 83)

12 (‒50 to 73)

10 (‒47 to 67)

9 (‒45 to 63)

p-values

-

n.s.

n.s.