Orofacial cleft defects: inference from nature and nurture

Area of Science:

• Genetics and Developmental Biology
• Teratology
• Pediatric Congenital Malformations

Background:

• Cleft lip with or without cleft palate (CL/P) and cleft palate (CP) are prevalent congenital malformations.
• Over a hundred Mendelian disorders are associated with these orofacial defects, defining syndromic forms.
• Genetic factors and environmental exposures play significant roles in the etiology of CL/P and CP.

Purpose of the Study:

• To review the genetic and environmental factors contributing to cleft lip/palate and cleft palate.
• To explore the inheritance patterns and specific genetic loci associated with these conditions.
• To discuss the role of teratogens and their interaction with genetic predispositions.

Main Methods:

• Review of genetic association studies, linkage analyses, and family-based studies.
• Analysis of data from animal models to understand etiology and pathogenesis.
• Examination of epidemiological evidence for environmental risk factors during early pregnancy.

Main Results:

• Both multigenic and monogenic inheritance patterns are observed in CL/P and CP.
• Specific genetic loci (e.g., EDN1, BCL3) and variations (e.g., TGF alpha) are linked to increased risk.
• Teratogens like ethanol and retinoids are confirmed risk factors, while others like caffeine require further investigation.

Conclusions:

• CL/P and CP result from complex interactions between genetic susceptibility and environmental influences.
• Understanding the genetic architecture and teratogenic exposures is vital for risk assessment and prevention strategies.
• Animal models are instrumental in elucidating the multifactorial etiology of orofacial clefts.