Contradiction with Genesis 25:1-2
Genesis 25:1-2 states that Abraham had additional sons with Keturah, whereas 1 Chronicles 1:28 only mentions Isaac and Ishmael as his sons, excluding Keturah's children.
Genesis 25:1-2: Then again Abraham took a wife, and her name [was] Keturah.
Contradiction with Genesis 16:15
Genesis 16:15 states Hagar bore Abraham a son named Ishmael but does not mention Isaac, while 1 Chronicles 1:28 includes both Isaac and Ishmael.
Genesis 16:15: And Hagar bare Abram a son: and Abram called his son's name, which Hagar bare, Ishmael.
Contradiction with Genesis 21:3
Genesis 21:3 points out that Sarah bore Isaac, indicating Sarah's specific contribution, whereas 1 Chronicles 1:28 categorizes Isaac alongside Ishmael without detailing their mothers.
Genesis 21:3: And Abraham called the name of his son that was born unto him, whom Sarah bare to him, Isaac.