When bestowing his patriarchal blessing upon Sam, Lehi simply said, "thy seed shall be numbered with his [Nephi's] seed" (2 Nephi 4:11), suggesting that Sam had daughters, but no sons.
According to Jerry Ainsworth, the Popul Vuh, an ancient history of the highland Maya, states that the original father of the Maya had four sons. One of them, not having male children, never became a tribe. Another ancient document, The Title of the Lords of Totonicapan, confirms the account in the Popul Vuh. It also adds that a total of eight men--possibly Nephi, Sam, Jacob, Joseph, Laman, Lemuel, and the sons of Ishmael--became seven tribes. These divided into two groups, one consisting of four tribes, the other of three. This agrees with the Book of Mormon account. [Jerry L. Ainsworth, The Lives and Travels of Mormon and Moroni, p. 88]