Is cleft lip/palate more predominant in low-income countries?

Cleft lip: I don't think so, but there is definitely some inhereted aspect of this deformity. Low income countries may not pay attention to the inheritance of this disease.

Yes: Yes it is and this has been related to nutritional deficiencies and prenatal care.

No.: Genetics plays a strong role in the prevalence of clefting in many countries. Asian is highest rate, then caucasian is lower, and black african rate is the lowest. Of course folate (folic acid) deficiency contributes, but does not seem responsible for national rate differences.