Consanguineous unions and the burden of disability: A population‐based study in communities of Northeastern Brazil

Abstract

Inbreeding increases the risk of disability which is unevenly distributed, varying considerably even in neighboring communities with similar Human Development Index and population density. Higher inbreeding communities are mostly located on the more economically underdeveloped backlands than on the coastal region. The identification of communities at high risk for genetic disorders could serve as basis for the establishment of Community Genetics programs.

A Community-Based Study of Mucopolysaccharidosis Type VI in Brazil: The Influence of Founder Effect, Endogamy and Consanguinity

“…They were between 4 and 23 years of age, and all of them were homozygous for the p.H178L missense mutation. The 4 deceased Monte Santo patients, 2 males and 2 females, were between 7 and 19 years of age at their death and, prior to death, they had also been shown to be homozygous for the p.H178L mutation ( table 1 ). By comparison, c.1533del23 has been reported to be the most common MPS VI mutation elsewhere in Brazil [22,23] .…”

“…As in other states of Northeast Brazil, e.g. Rio Grande do Norte and Paraíba [18,19] , there is a strong tradition of community endogamy and consanguineous marriage, in part due to geographical and social isolation. To date, 13 cases of MPS VI, 9 living and 4 now deceased, have been confirmed by clinical examination and genomic analysis, and each of these patients was shown to be homozygous for the ARSB p.H178L missense mutation.…”

Genetics and genomics in Brazil: a promising future

“…1A). Even though inbreeding has been decreasing in all Brazilian regions in the past decades, large differences between Southern and Northeastern populations still remain, with the coefficient of inbreeding ( f ) 13 times higher in some Northeastern ( f = 0.00395; proportion of consanguineous marriage from 6% to 12%) populations as compared to Southern ( f = 0.0003) populations (Freire-Maia 1957, 1989; Brito et al 2011; Weller et al 2012; Machado et al 2013), where the frequency of consanguineous marriage (<5%) is comparable to the estimates found for most of the other countries around the world (Hamamy et al 2011). …”

Homozygous missense mutation inMED25segregates with syndromic intellectual disability in a large consanguineous family

“…In Brazil, the frequency of consanguineous marriages is about 15 times higher in the Northeast region (9%) than in the Southern part of the country (0.62%) 6–8. A study conducted in small communities in Northeastern Brazil identified rates of consanguineous unions ranging from 6% to 41.1% 9. As part of a research project on consanguinity and disability aiming the identification of new disease genes, which is being performed in the backlands of Northeastern Brazil, we ascertained several families with multiple individuals with disabilities and selected some of them for additional investigation.…”