Consanguinity in South America: demographic aspects

Area of Science:

• Medical Genetics
• Population Genetics
• Epidemiology

Background:

• Consanguinity, defined as mating between related individuals, can increase the risk of autosomal recessive disorders.
• Understanding consanguinity patterns is crucial for public health initiatives and genetic counseling.

Purpose of the Study:

• To investigate the prevalence and patterns of consanguinity in a large Latin American population.
• To identify demographic and socioeconomic factors associated with consanguinity.

Main Methods:

• Analysis of data from 53,552 nonmalformed liveborn infants collected by the Latin-American Collaborative Study of Congenital Malformations (ECLAMC) from 1967 to 1996.
• Calculation of mean consanguinity rates and examination of associations with paternal education and occupation.
• Categorization of consanguineous unions by degree of relationship.

Main Results:

• The overall mean consanguinity rate was 0.96%, with significant regional variations (higher in Brazil and Venezuela, lower in Argentina).
• Low paternal education and occupation levels showed a positive association with consanguinity.
• First-cousin marriages constituted nearly half of all consanguineous unions.
• Brazil exhibited a predominance of closely related unions, whereas Venezuela showed more remote types, potentially reflecting differing migration histories.

Conclusions:

• Consanguinity rates and types in Latin America are geographically heterogeneous and associated with socioeconomic factors.
• Observed differences in consanguinity patterns between Brazil and Venezuela may be influenced by distinct migration dynamics.
• These findings underscore the importance of considering regional variations and socioeconomic determinants in the study of consanguinity.