Orofacial clefts, the most common congenital craniofacial malformations, have a complex etiology involving an interaction between genetic and environmental factors.

Chromosomal abnormalities, including structural variations, represent a major cause of human pathology. Recently, technological developments and the introduction of next-generation sequencing (NGS) technologies have revolutionized the field of medical genetics.

Optical genome mapping (OGM) is an innovative, high-resolution "long read" technique that enables the identification of all classes of chromosomal variation, consisting in the direct visualization of long, labeled DNA molecules throughout the genome. This technology is gradually becoming an essential tool for studying onco-hematology and constitutional genetic pathologies The purpose of this study is to search for structural chromosomal variants (SV) or copy number variants (CNV) not identifiable either by cytogenetic methods nor by "short read" NGS "short read, in individuals with oral-facial clefts with no genetic diagnosis.

Inclusion Criteria:

• Individuals with syndromic, complex or familial oral-facial clefts
• With no established genetic diagnosis
• Followed up at the Amiens-Picardie University Hospital

Exclusion Criteria:

• genetic diagnosis of oral-facial cleft
• No health insurance affiliation
• Patient under guardianship or curatorship, under safeguard of justice or deprived under public law
• Pregnant, parturient or breast-feeding woman