Article 491 of Jaafari Personal Status Law

An exception to the preceding article applies if the deceased leaves a son of a full paternal uncle together with a paternal uncle related through the father only: the paternal uncle's son excludes the paternal uncle, and the entire estate belongs to him, and the paternal uncle related through the father does not inherit with him at all. If there is with them a maternal uncle or a maternal aunt, the paternal uncle's son is excluded, and the inheritance goes to the paternal uncle, maternal uncle, and maternal aunt.