No one knows exactly what causes clefts, but most believe they are caused by one or more of three main factors:

• An inherited characteristic (gene) from one or both parents
• Environment (poor early pregnancy health or exposure to toxins such as alcohol or cocaine)
• Genetic syndromes

Cleft lip/palate is a part of more than 400 syndromes including Waardenburg, Pierre Robin, and Down syndromes. Approximately 30% of cleft deformities are associated with a syndrome, so a thorough medical evaluation and genetic counseling is recommended for cleft patients.