Severe congenital myasthenia gravis of the presynaptic type with choline acetyltransferase mutation in a Chinese infant with respiratory failure.
Neonatology
; 95(2): 183-6, 2009.
Article
en En
| MEDLINE
| ID: mdl-18797171
We report a severe case of congenital myasthenia gravis in a Chinese newborn who presented with complete ptosis, severe hypotonia, dysphagia and respiratory insufficiency with recurrent apnea that required mechanical ventilatory support since birth. Routine neurophysiologic studies, including the 3-Hz repetitive stimulation test and electromyogram were normal. Neostigmine and edrophonium tests were also negative. However, decremental response to 3-Hz stimulation became apparent after depleting the muscles with trains of 10-Hz stimuli for 10 min. The infant was subsequently confirmed to have heterozygous mutations in the choline acetyltransferase genes, p.T553N and p.S704P. Both missense mutations are novel mutations. The child remained on positive pressure ventilation at 3 years of age despite treatment with high-dose anticholinesterase. This case highlights the difficulty of making an early diagnosis based on clinical presentation and routine electrophysiologic tests, especially when neonatologists are not familiar with this condition. Further, as there are different genetic defects causing different types of congenital myasthenia gravis, anticholinesterase therapy may be beneficial to some but detrimental to others. Therefore, the exact molecular diagnosis is an important guide to therapy. A high index of suspicion coupled with extended electrodiagnostic tests in clinically suspected patients will ensure the selection of appropriate genetic molecular study for confirming the diagnosis.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Insuficiencia Respiratoria
/
Colina O-Acetiltransferasa
/
Síndromes Miasténicos Congénitos
/
Mutación
Tipo de estudio:
Diagnostic_studies
/
Etiology_studies
/
Screening_studies
Límite:
Female
/
Humans
/
Newborn
Idioma:
En
Revista:
Neonatology
Asunto de la revista:
PERINATOLOGIA
Año:
2009
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
Suiza