Charles Ellicott Commentary 2 Kings 1:17

"So he died according to the word of Jehovah which Elijah had spoken. And Jehoram began to reign in his stead in the second year of Jehoram the son of Jehoshaphat king of Judah; because he had no son." — 2 Kings 1:17 (ASV)

And Jehoram. —The LXX (Alexandrian text), Syriac, and Vulgate add “his brother,” an expression that has fallen out of the Hebrew text owing to its resemblance to the next (tahtâw, “in his stead”). (Compare to 2 Kings 3:1, “son of Ahab.”)

In the second year of Jehoram. —The Vatican Septuagint has “in the eighteenth year,” which is probably right. (Compare to 1 Kings 22:52, “Ahaziah ... reigned over Israel in ... the seventeenth year of Jehoshaphat ... and he reigned two years.” Either, therefore, our present Hebrew text is corrupt, or the compiler followed a different source in this place.) Thenius proposes the reading, “in the twenty-second year of Jehoshaphat,” in place of “in the second year of Jehoram the son of Jehoshaphat.”