The first symptom after normal development is usually [[hypotonia]], which is loss of muscle tone. Loss in manual dexterity and speech can then follow, as well as problems crawling or walking and diminished eye contact. Sudden onset of symptoms, including compulsive hand movements, can occur. | The first symptom after normal development is usually [[hypotonia]], which is loss of muscle tone. Loss in manual dexterity and speech can then follow, as well as problems crawling or walking and diminished eye contact. Sudden onset of symptoms, including compulsive hand movements, can occur. |