Increased concordance of severe respiratory syncytial virus infection in identical twins.
OBJECTIVE
We estimated differences in the severity of respiratory syncytial virus infection attributable to genetic and environmental factors.


METHODS
Record linkage data on hospitalizations attributable to respiratory syncytial virus infection were gathered on all twins (12,346 pairs) born in Denmark between 1994 and 2003. Latent-factor models of genetic and environmental effects were fitted to the observed data by using maximal likelihood methods.


RESULTS
Identical twins resembled each other significantly more than did fraternal twins for respiratory syncytial virus hospitalization (concordance rate: 0.66 vs 0.53), which suggests genetic influences on disease severity. Genetic factors accounted for 16%, family environment for 73%, and nonshared environment for 11% of the individual susceptibility to develop severe respiratory syncytial virus infection.


CONCLUSIONS
The severity of respiratory syncytial virus infection is determined partly by genetic factors. This result should stimulate the search for genetic markers of disease severity.
Thomsen
Simon Francis
SF
Department of Respiratory Medicine, Bispebjerg Hospital, Bispebjerg Bakke 23, Building 60 DK-2400 Copenhagen NV, Denmark. sft@city.dk
Stensballe
Lone Graff
LG
Skytthe
Axel
A
Kyvik
Kirsten Ohm
KO
Backer
Vibeke
V
Bisgaard
Hans
H
D017677:Age Distribution; D000956:Antigens, Viral / Q000032:analysis; D002675:Child, Preschool; D016001:Confidence Intervals; D003718:Denmark / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D011336:Probability; D016016:Proportional Hazards Models; D012042:Registries; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics*; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D014430:Twins, Monozygotic
D000956:Antigens, Viral