- Compound heterozygosity for missense (L156P) and nonsense (R554X) mutations in the beta4 integrin gene (ITGB4) underlies mild, nonlethal phenotype of epidermolysis bullosa with pyloric atresia. Pulkkinen, L., Bruckner-Tuderman, L., August, C., Uitto, J. Am. J. Pathol. (1998)