The presence of TLR4 mutations (Asp299Gly and Thr399Ile) were associated with severe RSV bronchiolitis and were significantly over-represented in groups II and III.
Each of the TLR4 mutations, either alone or in cosegregation, were associated with severe RSV bronchiolitis: the Asp299Gly and Thr399Ile mutations were significantly overrepresented in group I, compared with groups II and III.