Fetal hydantoin syndrome

Alternate names

Dilantin Embryopathy; Phenytoin Embryopathy

Definition

Fetal hydantoin syndrome is a disorder that is caused by exposure of a fetus to phenytoin, a drug commonly prescribed for epilepsy. Not all infants exposed to phenytoin will be affected with the disorder.

Signs and symptoms

There is a wide range in the nature and severity of characteristics associated with fetal hydantoin syndrome. Of infants born to women who used phenytoin during pregnancy, 10-30% are reported to show some of the characteristics associated with this syndrome. Few infants exposed only to phenytoin have all of the characteristic that have been reported. Children with this condition may be small at birth, with increased hair on the body and face, and with poorly developed fingernails and toenails.They may also have poor muscle tone. Facial features that may be present with this syndrome include a flat bridge of the nose; an underdeveloped vertical groove in the center of the upper lip (philtrum); a large mouth; and malformed ears. Features specific to the eyes may include down-slanted eyes; widely spaced eyes (hypertelorism); crossed eyes (strabismus); drooping eyelids (ptosis); and/or epicanthal folds (skin folds of the eyelid covering the inner corner of the eye). Other features that have been reported include a short or webbed neck and low-set hair line. Growth deficiencies may include underdeveloped fingers and/or toes, malformed nails, as well as finger-like thumbs. These features are often associated with growth delay and varying degrees of developmental delay. The risk for an affected child to be neurologically impaired is estimated at 1 to 11 % (two to three times higher than for the general population). The risk of cleft lip and/or palate and heart defects is estimated to be about five times higher among exposed infants. Some case reports have suggested an increased risk for the occurrence of benign (noncancerous) or malignant (cancerous) tumors, such as neuroblastoma or other neonatal tumors (ependymoma, ectodermal tumors, Wilms tumor).

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. 80%-99% of people have these symptoms

• Abnormal dermatoglyphics(Abnormal fingerprints)
• Abnormality of the pinna(Abnormally shaped ears)
• Depressed nasal ridge(Flat nose)
• Hearing abnormality(Abnormal hearing)
• Low-set, posteriorly rotated ears
• Short nose(Decreased length of nose)

30%-79% of people have these symptoms

• Abnormality of the fontanelles or cranial sutures
• Bifid scrotum(Cleft of scrotum)
• Coarse hair(Coarse hair texture)
• Epicanthus(Eye folds)
• Everted lower lip vermilion(Drooping lower lip)
• Global developmental delay
• Hernia
• Hypertelorism(Wide-set eyes)
• Hypoplastic fingernail(Small fingernail)
• Intrauterine growth retardation(Prenatal growth deficiency)
• Low posterior hairline(Low hairline at back of neck)
• Microcephaly(Abnormally small skull)
• Ptosis(Drooping upper eyelid)
• Short distal phalanx of finger(Short outermost finger bone)
• Short stature(Decreased body height)
• Strabismus(Cross-eyed)
• Thickened nuchal skin fold(Thickened skin folds of neck)
• Triphalangeal thumb(Finger-like thumb)
• Wide intermamillary distance(Wide-spaced nipples)
• Wide mouth(Broad mouth)

5%-29% of people have these symptoms

• Abnormality of the cardiovascular system(Cardiovascular abnormality)
• Cleft palate(Cleft roof of mouth)
• Cryptorchidism(Undescended testes)
• Neoplasm

Diagnosis

• There is no diagnostic testing that can identify fetal hydantoin syndrome.
• A diagnosis is made clinically based upon identification of characteristic symptoms in an affected infant in conjunction with a history of phenytoin exposure during gestation. It is important to note that the majority of infants born to women who take phenytoin during pregnancy will not develop fetal hydantoin syndrome.

Treatment

• Treatment may include surgery for cleft lip and palate and special education and related services for children with learning delays.
• Other treatment is symptomatic and supportive.

NIH genetic and rare disease info

• NIH info on Fetal hydantoin syndrome

Fetal hydantoin syndrome is a rare disease.

Fetal hydantoin syndrome Resources
Latest articles Most recent articles Ongoing trials	Wikipedia