From 2 Nephi we read this incredible prediction made over two thousand years ago which named names of a literal Israelite descendent.
4 For behold, thou art the fruit of my loins; and I am a descendant of Joseph who was carried captive into Egypt. And great were the covenants of the Lord which he made unto Joseph.
5 Wherefore, Joseph truly saw our day. And he obtained a promise of the Lord, that out of the fruit of his loins the Lord God would raise up a righteous branch unto the house of Israel; not the Messiah, but a branch which was to be broken off, nevertheless, to be remembered in the covenants of the Lord that the Messiah should be made manifest unto them in the latter days, in the spirit of power, unto the bringing of them out of darkness unto light—yea, out of hidden darkness and out of captivity unto freedom.
6 For Joseph truly testified, saying: A seer shall the Lord my God raise up, who shall be a choice seer unto the fruit of my loins.
7 Yea, Joseph truly said: Thus saith the Lord unto me: A choice seer will I raise up out of the fruit of thy loins; and he shall be esteemed highly among the fruit of thy loins. And unto him will I give commandment that he shall do a work for the fruit of thy loins, his brethren, which shall be of great worth unto them, even to the bringing of them to the knowledge of the covenants which I have made with thy fathers.
8 And I will give unto him a commandment that he shall do none other work, save the work which I shall command him. And I will make him great in mine eyes; for he shall do my work.
9 And he shall be great like unto Moses, whom I have said I would raise up unto you, to deliver my people, O house of Israel.
10 And Moses will I raise up, to deliver thy people out of the land of Egypt.
11 But a seer will I raise up out of the fruit of thy loins; and unto him will I give power to bring forth my word unto the seed of thy loins—and not to the bringing forth my word only, saith the Lord, but to the convincing them of my word, which shall have already gone forth among them.
12 Wherefore, the fruit of thy loins shall write; and the fruit of the loins of Judah shall write; and that which shall be written by the fruit of thy loins, and also that which shall be written by the fruit of the loins of Judah, shall grow together, unto the confounding of false doctrines and laying down of contentions, and establishing peace among the fruit of thy loins, and bringing them to the knowledge of their fathers in the latter days, and also to the knowledge of my covenants, saith the Lord.
13 And out of weakness he shall be made strong, in that day when my work shall commence among all my people, unto the restoring thee, O house of Israel, saith the Lord.
14 And thus prophesied Joseph, saying: Behold, that seer will the Lord bless; and they that seek to destroy him shall be confounded; for this promise, which I have obtained of the Lord, of the fruit of my loins, shall be fulfilled. Behold, I am sure of the fulfilling of this promise;
15 And his name shall be called after me; and it shall be after the name of his father. And he shall be like unto me; for the thing, which the Lord shall bring forth by his hand, by the power of the Lord shall bring my people unto salvation.
So Joseph Smith Jr. and his father Joseph Smith Sr should have some middle eastern ancestors. Should be fairly easy to find a living descendent and check their DNA. Eldred G. Smith the great great grandson of Hyrum Smith and the last church patriarch, died in 2013 leaving over 100 direct descendants. There is a data pool for someone to check.