TY - JOUR

T1 - Concordance for multiple sclerosis in Danish twins

T2 - an update of a nationwide study

AU - Hansen, T

AU - Skytthe, Axel

AU - Stenager, Egon

AU - Petersen, H C

AU - Brønnum-Hansen, Henrik

AU - Kyvik, K O

PY - 2005

Y1 - 2005

N2 - The occurrence of multiple sclerosis (MS) in twins has not previously been studied in complete nationwide data sets. The existence of almost complete MS and twin registries in Denmark ensures that essentially unbiased samples of MS cases among twins can be obtained. In this population-based study, virtually all Danish MS cases among twins born before 1983 with onset of MS after 1948 and diagnosis before I January 1997 were identified. Of 13 286 MS cases, 178 were twins and, of these 164 twin pairs were discordant and seven were concordant. We found significantly higher proband-wise concordance among monozygotic twins than dizygotic twins, with estimated proband-wise concordances of 24% (95% confidence interval (CI): 5-39%) for monozygotic and 3% (95% CI: 0-8%) for dizygotic twins. Thus, a monozygotic twin whose co-twin has MS has a 24% risk of developing the disease, while the corresponding risk for a dizygotic twin is only 3%. Our results largely confirm previously published concordance estimates and indicate that genetic factors are of importance in susceptibility to MS.

AB - The occurrence of multiple sclerosis (MS) in twins has not previously been studied in complete nationwide data sets. The existence of almost complete MS and twin registries in Denmark ensures that essentially unbiased samples of MS cases among twins can be obtained. In this population-based study, virtually all Danish MS cases among twins born before 1983 with onset of MS after 1948 and diagnosis before I January 1997 were identified. Of 13 286 MS cases, 178 were twins and, of these 164 twin pairs were discordant and seven were concordant. We found significantly higher proband-wise concordance among monozygotic twins than dizygotic twins, with estimated proband-wise concordances of 24% (95% confidence interval (CI): 5-39%) for monozygotic and 3% (95% CI: 0-8%) for dizygotic twins. Thus, a monozygotic twin whose co-twin has MS has a 24% risk of developing the disease, while the corresponding risk for a dizygotic twin is only 3%. Our results largely confirm previously published concordance estimates and indicate that genetic factors are of importance in susceptibility to MS.

KW - Adult

KW - Aged

KW - Aged, 80 and over

KW - Denmark

KW - Female

KW - Genetic Predisposition to Disease

KW - Humans

KW - Male

KW - Middle Aged

KW - Multiple Sclerosis

KW - Registries

KW - Risk Factors

KW - Sex Distribution

KW - Twins, Dizygotic

KW - Twins, Monozygotic

M3 - Journal article

C2 - 16193885

VL - 11

SP - 504

EP - 510

JO - Multiple Sclerosis Journal

JF - Multiple Sclerosis Journal

SN - 1352-4585

IS - 5

ER -