CONCLUSIONS
In this study, we found that the childhood asthma risk increased by the number of family members affected by asthma. A family history of a grandparent with asthma was associated with childhood asthma and the association was only partially mediated by parent with asthma. In addition, children who had father and parental grandfather with asthma had similar magnitude of asthma risk with those who have both parents with asthma. Our findings could be used to identify children at high risk for asthma in early childhood.