What is Consanguinity?
Consanguinity or kinship is characterized by the sharing of common ancestors. The word is derived from
the Latin consanguineus, meaning 'of common blood'. Consanguineous persons have at least one common
ancestor in the preceding few generations. A consanguineous marriage is one in which two individuals
related by blood, such as cousins, get married and have children.
Genes, which occur in pairs, are packages of information that we inherit from our parents. The risk of
birth defects is higher in consanguineous marriages because there is a greater chance of two related
individuals sharing a common harmful gene and both of them passing it on to the child.
The risk and type of birth defects in consanguineous marriages varies according to how closely the couple
is related. Most consanguineous couples can have normal healthy children.
Both parents give one copy. When these two are paired together, sometimes one
dominates over the other, which means the trait will "show" even if only one copy is
present. The trait that is hidden is called recessive. If each parent
gives a copy of the recessive trait however, there is no trait to dominate over
it and the recessive trait will show. This is why we say that sometimes
traits "skip a generation" (not always true!) or there is a hidden trait in a
family. If one of these recessive traits being carried in people in the family, with every generation
there is a greater chance that two carriers could come together and each
donate a recessive trait. In other words, there is a greater PROBABILITY that
this trait will show up in a close family mating than in the general population.
If there are no traits in the family however, the likelihood
that first cousins will have problems is no greater than the general population.
So it depends on a lot of factors.
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