The marriage of the same descendants is called a
consanguineous marriage. Kinship; it can come from the mother line, as well as
the father line. Both are equally important. Consanguineous marriage is
generally examined at two levels: Marriages by a couple whose mother or father
are siblings are called 1st degree relative marriage (Cousin Marriages).
Marriage between couples whose grandparents are siblings is called a second
degree relative marriage.
What kind
of risks do consanguineous marriages cause?
It has been reported that the frequency of stillbirth in
relatives who have consanguineous marriages has increased approximately 2 times
compared to normal society (1.24% in normal society, 2.14% in consanguineous
marriages). When low and stillbirths are considered together, the same increase
is also remarkable (5.21% in normal society, 10.55% in consanguineous
marriages). In terms of newborn losses, there is an increase of 50% (10.76% in
normal society, 16.29% in consanguineous marriages). In addition, it is
reported that birth defects increase 10 times in consanguineous marriages.
Consanguineous marriages increase the incidence of diseases
with autosomal recessive and multi-factor inheritance. Genes are structures
that enable the transfer of features from parents to children. The likelihood
of similarity among genes in the same family is very high since they are
transferred from parents to children. In diseases that increase the risk of
being seen with consanguineous marriages, both spouses must have the same type
of defective genes. As the frequency of similarity among genes increases among
relatives, the probability of having a child with illness also increases among
relatives.
Matching of mother and father blood groups does not indicate
that there is no risk. The risks associated with blood incompatibility and
consanguineous marriage are completely irrelevant.
People with disabilities (such as blind, deaf) are not
recommended to marry the same disabled people. If people with the same
disability get married, the risk is high in the baby.
Can
relatives marry a healthy child?
It may happen, but those who have consanguineous marriages
have an increased risk of having a diseased baby compared to other marriages.
The most important point that misleads families is that healthy children are
born from the consanguineous marriages that others do in their own family and
environment. Just because the family has healthy children from previous
pregnancies does not show that there is no risk in subsequent pregnancies, or
that they have sick children before does not indicate that they will not have
healthy children. These couples have an increased risk of having a diseased
baby, but about 95% of children born are completely healthy. It can be both healthy
and sick children from the same parent.
How to
watch couples who have consanguineous marriage?
First, a family tree of 3 generations should be drawn and
information about each individual should be obtained. If symptoms of any
disease are detected in the family tree, information about this condition
should be obtained. Medical records, photographs and information provided by
the family should be evaluated. If necessary, experts in the relevant branch
should be consulted. Risk calculation is made for the individual we investigate
according to the heredity pattern of the disease. If there is an increased
risk, tests for this disease are planned and according to the test results, if
there is a risk in the pregnancy of the family, prenatal diagnosis should be
planned.
What should
be followed during pregnancy in consanguineous marriage?
These families should be followed up during pregnancy,
biochemical screening test during pregnancy, second-line USG follow-up, and
evaluation of their babies at birth, and research for hearing loss and
metabolic diseases. Double, triple, and quadruple tests and detailed
ultrsonography performed in normal pregnancies are also performed in these
pregnancies. Double, triple, and quadruple tests do not show hereditary
diseases with consanguineous marriage. It is performed only for the purpose of
screening for chromosomal anomalies as in normal pregnancies. In consanguineous
marriages, some diseases can be detected with CVS (chorionic villus sampling)
performed between 11-14 weeks when necessary, and in this case, the family may
request the termination of pregnancy.
In
consanguineous marriages, the risk of a diseased baby can be prevented with the
PGD method:
With this method, an embryo is created by fertilizing the
eggs and sperm taken from the mother and father in the external environment. In
the cell sample taken from the embryo formed, the presence of some diseases is
investigated and the embryo without disease is transferred to the mother's
uterus.
-HOW TO SLEEP IN PREGNANCY?
-WHEN DO BABY MOVEMENTS START IN PREGNANCY?
-BABY'S LENGTH AND WEIGHT BY WEEKS
-PHYSIOLOGICAL CHANGES IN THE BODY IN PREGNANCY
