Fetal Hydantoin Syndrome
National Organization for Rare Disorders, Inc.
It is possible that the main title of the report Fetal Hydantoin Syndrome is not the name you expected.
Fetal hydantoin syndrome is a characteristic pattern of mental and physical birth defects that results from maternal use of the anti-seizure (anticonvulsant) drug phenytoin (Dilantin) during pregnancy. The range and severity of associated abnormalities will vary greatly from one infant to another. However, characteristic features may include distinctive skull and facial features, growth deficiencies, underdeveloped (hypoplastic) nails of the fingers and toes, and/or mild developmental delays. Other findings occasionally associated with this syndrome include cleft lip and palate, a head circumference that is smaller than would be expected based upon an infant's age and gender (microcephaly), and skeletal malformations particularly of the fingers or hands. The exact risk of a fetus developing fetal hydantoin syndrome is not fully understood, but only approximately 5-10% of fetuses exposed to phenytoin develop the disorder.
Anti-seizure medications, also known as antiepileptic or anticonvulsant medications are among the most common teratogens prescribed to women of childbearing age. A teratogen is a drug that interferes with the development of a fetus. Affected infants often develop similar symptoms regardless of the associated drug, particularly symptoms affecting the head and face region (craniofacial abnormalities). Studies have indicated that fetal valproate syndrome is associated with greater risk of neurological and cognitive abnormalities than other anti-seizure medications. NORD has a separate report on fetal valproate syndrome.
Although some disorders due to specific drugs (e.g. fetal hydantoin syndrome) are rare, many researchers believe that when considering the teratogenic effects of all antiepileptic drugs collectively these disorders are not rare. The concept of fetal antiepileptic syndromes in this regard is less useful than in the past and the broad consideration of the major and minor congenital malformations, various cognitive impairments, and behavioral abnormalities taken as a broader, collective concept is more appropriate.
American Cleft Palate-Craniofacial Association
- 1504 East Franklin Street
- Suite 102
- Chapel Hill, NC 27514-2820
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- Website: http://www.cleftline.org
Cleft Lip and Palate Foundation of Smiles
- 2044 Michael Ave SW
- Wyoming, MI 49509
- Tel: (616)329-1335
- Email: Rachelmancuso09@comcast.net
- Website: http://www.cleftsmile.org
Genetic and Rare Diseases (GARD) Information Center
- PO Box 8126
- Gaithersburg, MD 20898-8126
- Tel: (301)251-4925
- Fax: (301)251-4911
- Tel: (888)205-2311
- Website: http://rarediseases.info.nih.gov/GARD/
March of Dimes
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- White Plains, NY 10605
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- Fax: (914)997-4763
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Organisation For Anti-Convulsant Syndrome
- 23 Morriston Close
- South Oxhey
- Watford, WD196UB
- United Kingdom
- Tel: 4402083869271
- Email: OACSsecretary@gmail.com
- Website: http://www.oacscharity.org
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- Website: http://www.thearc.org
For a Complete Report
This is an abstract of a report from the National Organization for Rare Disorders (NORD). For a full-text version of this report, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".
The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only.
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This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.
Last Updated: 7/6/2015
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