Loeys–Dietz syndrome can cause cleft palate or bifid uvula, hypertelorism, and aortic aneurysm. Hardikar syndrome can cause cleft lip and palate, Hydronephrosis, Intestinal obstruction and other symptoms. Cleft lip/palate may be present in many different chromosome disorders including Patau syndrome (trisomy 13). Malpuech facial clefting syndrome
Hearing loss with craniofacial syndromes
Popliteal pterygium syndrome
Cornelia de Lange syndrome
Treacher Collins syndrome
Pierre Robin syndrome

Specific genes
Many genes associated with syndromic cases of cleft lip/palate (see above) have been identified to contribute to the incidence of isolated cases of cleft lip/palate. This includes in particular sequence variants in the genes IRF6, PVRL1 and MSX1. The understanding of the genetic complexities involved in the morphogenesis of the midface, including molecular and cellular processes, has been greatly aided by research on animal models, including of the genes BMP4, SHH, SHOX2, FGF10 and MSX1. Environmental factors
Environmental influences may also cause, or interact with genetics to produce, orofacial clefts. An example of the link between environmental factors and genetics comes from a research on mutations in the gene PHF8. The research found that PHF8 encodes for a histone lysine demethylase, and is involved in epigenetic regulation. The catalytic activity of PHF8 depends on molecular oxygen, a factor considered important from reports on increased incidence of cleft lip/palate in mice that have been exposed to hypoxia early during pregnancy.Cleft lip and other congenital abnormalities have also been linked to maternal hypoxia caused by maternal smoking, with the estimated attributable fraction of orofacial clefts due to smoking in early pregnancy being 6.1%.
A cleft lip contains an opening in the upper lip that may extend into the nose. The opening may be on one side, both sides, or in the middle. A cleft palate occurs when the palate (the roof of the mouth) contains an opening into the nose. The term orofacial cleft refers to either condition or to both occurring together. These disorders can result in feeding problems, speech problems, hearing problems, and frequent ear infections. Less than half the time the condition is associated with other disorders.Cleft lip and palate are the result of tissues of the face not joining properly during development. As such, they are a type of birth defect. The cause is unknown in most cases. Risk factors include smoking during pregnancy, diabetes, obesity, an older mother, and certain medications (such as some used to treat seizures). Cleft lip and cleft palate can often be diagnosed during pregnancy with an ultrasound exam.A cleft lip or palate can be successfully treated with surgery. This is often done in the first few months of life for cleft lip and before eighteen months for cleft palate. Speech therapy and dental care may also be needed. With appropriate treatment, outcomes are good.Cleft lip and palate occurs in about 1 to 2 per 1000 births in the developed world. Cleft lip is about twice as common in males as females, while cleft palate without cleft lip is more common in females. In 2017, it resulted in about 3,800 deaths globally, down from 14,600 deaths in 1990.