Genetics is the study of genes. Genes are the smallest unit of
heredity (heredity is the passing of genes from one generation to
the next). Each cell in the human body contains genes, which
contain the "blueprint" for everything in our bodies, such as our
height, hair color, skin color, eye color, etc. Genetic
inheritance means that a child's features are "inherited," or
passed from parent to child. Your child may have "inherited" his
cleft from one or both parents.
There are two types of inheritance:
- Single gene inheritance: a feature appears as a result of a
single gene carried by one parent.
- Multifactorial inheritance: a feature appears as a result of
a number of genetic and non-genetic factors, such as alcohol,
drugs, environmental factors, etc.
Other factors can also occur during pregnancy to cause cleft lip
and palate. Sometimes a group of problems appear together in
newborn babies. These groups are called syndromes. A cleft lip or
palate may be only one part of a larger syndrome. Like clefts,
syndromes may be a result of a single gene or multifactorial
inheritance. The exact cause of cleft is often unknown. The
geneticist or genetic counselor can help you try to find the
reason for your child's cleft. Your geneticist will also discuss
your risk of having another child with cleft.