Clefts of the lip or palate have many causes. One is Van der Woude Syndrome
(VWS), an inherited disorder. Inherited disorders are passed from parent to
child through genes. About three percent of people with a cleft have VWS. Features
of VWS include:
- mounds or depressions (pits) on the lower lip
- cleft lip, with or without cleft palate
- cleft palate alone
- missing teeth
People who show signs of VWS may have one or more of these features. It is
the lip pits or mounds that set VWS apart from other types.
Lip mounds in patient with Van der Woude Syndrome
Lip pits in patient with Van der Woude Syndrome
What causes VWS?
Genes, the basic units of heredity, contain blueprints for human growth and
development. Genes are found on chromosomes. Humans have 46 chromosomes, 23
coming from the mother and 23 coming from the father. A change or alteration
in a single gene on chromosome number one causes VWS. Of the people who inherit this altered gene, 95 percent have some features of VWS. Some people who inherit an altered VWS gene do not show any features.
Cell - Nucleus - Chromosome - DNA Strand - Gene Code
Can future children also have VWS?
VWS is inherited in an autosomal dominant pattern. In VWS, the altered gene
is the dominant gene. This means the person with an altered VWS gene usually
has some feature of the syndrome. People with VWS have a 50 percent chance
of passing the dominant, altered gene on to each of their children, regardless
of the sex of the child. They also have a 50 percent chance of passing the normal gene to their children. Children who inherit the unaltered gene will not have VWS and thus cannot pass VWS on to future children. The severity of VWS features cannot be predicted even within a family. It is not known why some people have lip pits only, some people have lip pits and a cleft, some people have only a cleft, while others do not show any features.
How will making this diagnosis help my child?
Seeking treatment early in your child's life allows for timely surgery, speech
therapy, and dental care. Questions about feeding concerns and your role in
your child's treatment can be answered early. A child with a cleft palate has
a higher risk for ear infections and speech problems which, if caught early,
can be treated. An early diagnosis of VWS allows couples planning to have children to assess their risk of having a child with VWS.
Ongoing research
Progress is being made in the search for the VWS gene. Researchers determined
that the gene is located on chromosome number one. They are now focusing their
efforts on finding the exact location of the gene on chromosome one. Once the
gene is found, researchers can study the function of the gene. Knowledge of
the function may lead to ways to prevent or improve the treatment of VWS. Finding the VWS gene may also lead to the development of a clinical genetic test.
How can I learn more about VWS?
- Craniofacial Anomalies Research Center
University of Iowa
140 Eckstein Medical Research Building
Iowa City, IA 52242
Toll Free: 866-520-8982
- Regional Genetic Consultation Service
Division of Medical Genetics
200 Hawkins Drive
Iow City, IA 52242
Tel: 319-356-2674
Other Resources
- American Cleft Palate-Craniofacial Association
Cleft Palate Foundation
104 South Estes Drive Suite 204
Chapel Hill, NC 27514
Tel: 919-933-9044
Toll Free: 800-242-5338
Fax: 919-933-9604
E-mail: cleftline@aol.com
www.cleftline.org
- Gene Clinics
www.genetests.org
- National Organization for Rare Diseases, Inc. (NORD)
P.O. Box 8923
New Fairfield, CT 06812-8923
Tel: 203-746-6518
Toll Free: 800-999-6673
Fax: 203-746-6481
E-mail: info@geneticalliance.org
- Online Mendelian Inheritance of Man (OMIM)
www.ncbi.nlm.nih.gov/Omim
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