Abstract
Background
Aromatic l-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive disorder
of neurotransmitter synthesis. It has unique clinical presentations.
Aims
The purpose of this study is to delineate the clinical features and molecular spectrum
of AADC deficiency in Taiwanese infants and children.
Methods
We report eight patients with characteristic clinical manifestations of AADC deficiency.
Clinical presentations, treatment response, outcome and mutations of DOPA decarboxylase
(DDC) gene were analyzed.
Results
The clinical manifestations were similar to those previously reported, including symptoms
onset before age 1 year with features of severe floppiness, oculogyric crises, athetoid
movement, prominent startle response, tongue thrusting, ptosis, paroxysmal diaphoresis,
nasal congestion, diarrhea, irritability and sleep disorders. In addition, we observed
that all patients (100.0%) had small hands and feet. During the period of follow-up,
all of them (100.0%) presented severe floppiness in spite of therapeutic trials with
vitamin B6, dopamine agonist, MAO inhibitor and/or anticholinergics. Three different
mutations were identified in the DDC gene, including two novel mutations 1303 C>T and 1367ins A and one IVS 6+4 A>T mutation. The IVS 6+4 A>T was a splicing mutation, which inserted an additional 37 nt of intron 6 into the DDC mRNA. Thirteen out of 16 alleles (81.3%) carried IVS 6+4 A>T mutation and the IVS 6+4 A>T alleles shared a conserved haplotype.
Conclusions
Patients with AADC deficiency in Taiwan have particular clinical manifestations of
small hands and feet, which have rarely been mentioned in the literature. The prevalence
of IVS 6+4 A>T splicing mutation is high in our study group and the IVS 6+4 A>T mutation might have a founder effect.
Keywords
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Article info
Publication history
Accepted:
March 8,
2008
Received in revised form:
February 25,
2008
Received:
October 7,
2007
Identification
Copyright
© 2008 European Paediatric Neurology Society. Published by Elsevier Inc. All rights reserved.
