Many of the other 12 cranial nerves may also be affected, including the 3rd, 5th, 8th, 9th, 11th and 12th. The most apparent symptoms are related to facial expressions and function. In newborn infants, the first sign is an impaired ability to suck. Excessive drooling and crossed eyes may be present. In addition, there can be deformities of the tongue and jaw, and even of some limbs, including club foot and missing or webbed fingers.
Most children have low muscle tone, particularly of the upper body.
Although they crawl and walk later, most Moebius Syndrome children eventually catch up. Speech problems often respond to therapy, but may persist due to impaired mobility of the tongue and lips. As children get older, the lack of facial expression and an inability to smile become the dominant visible symptoms. Moebius Syndrome is sometimes accompanied by Pierre Robin Syndrome and Poland's Anomaly. Children are born with it.