This advice-column-style blog for SLPs was authored by Pam Marshalla from 2006 to 2015, the archives of which can be explored here. Use the extensive keywords list found in the right-hand column (on mobile: at the bottom of the page) to browse specific topics, or use the search feature to locate specific words or phrases throughout the entire blog.
Q: I have a relative who does not have any movement of her top lip. She cannot blow a horn and has difficult with straw sucking. Her 4-year-old son also was born with this lack of movement with his upper lip. What could this be?
It sounds like it could be Mobious Syndrome (Alternative spellings: Mobius, Moebius).
Mobious Syndrome has many characteristics, including partial facial and lip paralysis. Speech can be bad if the paralysis is wide spread in the facial and oral area. But the milder patients greatest problem is not being able to smile and use a straw. I would have her talk to her doctor about it. She probably will have to see a neurologist for the definitive diagnosis.
A quick web search revealed many sites with information. For easy-to-read quick information, I liked this page from DentalResource.org.