This review analyzed an epigenome-wide association study involving 32 monozygotic and 22 dizygotic twin pairs. In these families, one twin had nonsyndromic cleft lip with or without cleft palate while the other twin was unaffected. The researchers looked for differences in DNA methylation, which are chemical tags on genes that can influence how they work.
The analysis identified significant methylation differences at the CYP26A1 locus and noted another strong signal at the ANKRD11 gene. The study also found that these changes occurred in areas of DNA known to regulate facial development. Additionally, the findings overlapped with genes previously linked to clefts in other large genetic studies.
Because this was a review of a specific type of study, the results show associations rather than direct causes. Readers should understand that having these DNA marks does not guarantee a child will have a cleft, nor does it mean the marks are the only factor. More research is needed to confirm these findings and understand their full role in facial development.