(Actual practicing "Mormon" here)
Actually, LDS Christians believe that Jesus Christ was conceived within the virgin Mary by the power of the Holy Spirit, as described in Luke.
99.9% of the time when somebody uses the term "Mormon" they are referring to the Church of Jesus Christ of Latter-Day Saints. Again, which believe that Mary was a virgin and Christ conceived by the Holy Spirit.
The groups that have broken away from the Church of Jesus Christ of Latter-Day Saints, such as Warren Jeff's group, are COMPLETELY separate: radically different beliefs, different scriptures, different practices, and consider the other to be excommunicate apostates.
That's completely distorted as to no longer resemble actual LDS Christian beliefs.
I'm sorry, but that's a complete fiction invented by "anti-cultists" . You're way better than that junk Paul. Disagree with beliefs all you want, but disagree with ACTUAL beliefs and not the fiction sold in "anti-cult" books. Nobody believes that fiction except for the poor chump whom bought the "anti cult" book (literally or figuratively).
@Grailhunter isn't a "Mormon" or more correctly, member of the Church of Jesus Christ of Latter Day Saints. With all due respect to him, a lot of the things he posts I, as an LDS Christian, PASSIONATLY disagree with.