A case of major form familial hyperekplexia: prenatal diagnosis and effective treatment with clonazepam.
Hyperekplexia (OMIM 149400) is an uncommon neurologic disorder characterized by exaggerated response to sensitive stimuli. It may be sporadic or familial. The disease is usually caused by mutations in the inhibitory glycine receptor alpha1-subunit. The authors report a male patient who is affected by the major form of familial hyperekplexia. He is currently 5 years old and is being successfully treated with clonazepam. Prenatal diagnosis was made owing to prior identification of point mutation K276E in his affected mother. Early diagnosis avoided complex and prolonged differential diagnostic procedures and allowed for early and effective intervention on severe neonatal symptoms: hypertonia, episodes of cyanosis, apneic spells, and massive myoclonic jerks. During his first year of life, the patient was treated with cycles of phenobarbital and diazepam and achieved partial clinical response. Subsequent therapy with low-dose clonazepam was highly effective in reducing myoclonic jerks and exaggerated startle reaction, and unlike previously used drugs, it was decisive in reducing hypertonia.
Doria Lamba
Laura
L
Department of Neuroscience, Ophthalmology and Genetics, University of Genoa, Children Neuropsychiatry Operative Unit, G Gaslini Institute, Genoa, Italy. lauradoria@ospedale-gaslini.ge.it
Giribaldi
Gaia
G
De Negri
Emanuela
E
Follo
Roberta
R
De Grandis
Elisa
E
Pintaudi
Maria
M
Veneselli
Edvige
E
D000927:Anticonvulsants / Q000627:therapeutic use*; D002675:Child, Preschool; D002998:Clonazepam / Q000627:therapeutic use*; D005192:Family Health; D005260:Female; D018698:Glutamic Acid / Q000235:genetics; D006801:Humans; D008239:Lysine / Q000235:genetics; D008297:Male; D009122:Muscle Hypertonia / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics; D017354:Point Mutation; D011247:Pregnancy; D011296:Prenatal Diagnosis; D018009:Receptors, Glycine / Q000235:genetics; D012021:Reflex, Abnormal
D000927:Anticonvulsants; D018009:Receptors, Glycine; D018698:Glutamic Acid; D002998:Clonazepam; D008239:Lysine