Definition: Effects due to maternal exposure to hydantoin anticonvulsant.
Synonyms: Dilantin, Phenytoin and a few other similar anticonvulsants are also included.
Incidence: 7-10% of exposed infants.
Etiology: Alteration of enzymatic pathways,. Sibs exposed to similar amount have been affected to different degrees.
Recurrence risk: None
Diagnosis: Growth retardation, microcephaly, hypoplasia of the distal phalanx of the fingers and toes, nail hypoplasia, typical facial appearance with a low nasal bridge, hirsutism and cleft-lip/palate, rib anomalies and occasionally cardiac and genito-urinary anomalies,,.
Genetic anomaly: None
Associated anomalies: None
Differential diagnosis: Other causes of growth restriction and cardiac anomalies, thus a TORCH titer and karyotype should be obtained.
Prognosis: Dependent on the severity of the case.
Management: Switch the mother to a different medication if possible. Some prenatal testing might be possible.
 Buehler BA, Rao V, Finnell RH Biochemical and molecular teratology of fetal hydantoin syndrome. Neurol Clin 1994 Nov;12(4):741-8
 Finnell RH, Buehler BA, Kerr BM, Ager PL, Levy RH Clinical and experimental studies linking oxidative metabolism to phenytoin-induced teratogenesis. Neurology 1992 Apr;42(4 Suppl 5):25-31
 Sabry MA, Farag TI Hand anomalies in fetal-hydantoin syndrome: from nail/phalangeal hypoplasia to unilateral acheiria. Am J Med Genet 1996 Apr 24;62(4):410-2
 Ozkinay F, Yenigun A, Kantar M, Ozkinay C, Avanoglu A, Ulman I Two siblings with fetal hydantoin syndrome. Turk J Pediatr 1998 Apr-Jun;40(2):273-8
 Adams J, Vorhees CV, Middaugh LD Developmental neurotoxicity of anticonvulsants: human and animal evidence on phenytoin. Neurotoxicol Teratol 1990 May-Jun;12(3):203-14
 Buehler BA, Delimont D, van Waes M, Finnell RH Prenatal prediction of risk of the fetal hydantoin syndrome. N Engl J Med 1990 May 31;322(22):1567-72