Complex segregation analysis of facial clefting in Chile

Area of Science:

• Genetics
• Pediatrics
• Public Health

Background:

• Nonsyndromic cleft lip with or without cleft palate (CL/P) presents a significant public health concern globally.
• Chile exhibits a high incidence of CL/P, comparable to Asian populations, suggesting unique genetic factors.
• The prevalence in Chile is noted as 1.5 per 1,000 live births, with slight variations between males (1.7 per 1,000) and females (1.3 per 1,000).

Purpose of the Study:

• To investigate the genetic transmission patterns of nonsyndromic cleft lip with or without cleft palate (CL/P) in Chilean populations.
• To identify the most parsimonious genetic model explaining the observed CL/P incidence and familial aggregation in Chile.

Main Methods:

• Complex segregation analysis was performed on 67 multigeneration Chilean pedigrees.
• Data included 162 affected individuals and 898 family members, analyzed using the PAP computer program.

Main Results:

• The analysis identified a statistically significant genetic component influencing CL/P.
• The most parsimonious model indicated the presence of an autosomal dominant gene.
• This gene exhibits reduced penetrance, estimated to be between 20% and 25%.

Conclusions:

• A single autosomal dominant gene with reduced penetrance is the most probable genetic mechanism for nonsyndromic cleft lip with or without cleft palate in the studied Chilean population.
• The high CL/P rates in Chile may be linked to Amerindian genetic contributions.
• Further research into specific genetic markers and environmental interactions is warranted.