UPDATE: Sidney Quintanilla has been found safe and has been reunited with her family, according to the Hidalgo County Sheriff's Office. 

The Hidalgo County Sheriff's Office has issued a regional alert for a missing 22-year-old woman. 

Sidney Quintanilla, 22, was last seen Wednesday at about 10 p.m. in the Mission area. 

Authorities say Quintanilla has been diagnosed with autism. She's five feet, 11 inches tall, weighs about 220 pounds and has brown eyes and black hair. 

If you've seen Quintanilla, call HCSO at 956-383-8114.