Marilyn Today, I received information that confirms your Great Grandfather Ireneus A. Geren, Columbus Ohio,born in 1845,was the brother of my Great Grandfather Dudley D. Geren, born in 1846. He was known to our family as "Uncle Reny"
I received an e-mail from a person with the book "The Gerens of Ohio."On back back page there were note that Dudley D. Geren married Adenia M. Wilson Jan 13 1876 and"Ivennis A. Geren" married Sarah A. McKetterick June 14, 1876.
Both brothers were bricklayers (masons) and they both served in the civil war (Batallion H 1 Ohio Light Artillery.)
I have a 1910 cenus record showing Ireneus living in Columbus on South Oakley St. He was 66 years old and he had another family: wife Pheba b. ~1871son Lawrence W.born ~ 1898and daughter Ruthborn ~ 1903.
I hope this is helpful for your family research.If you have anything that ties these brothers back to the earlier Ireneus A. Geren (b. 1825 in Marietta.) it would be very useful.