Findings of amplitude-integrated electroencephalogram recordings and serum vitamin B6 metabolites in perinatal lethal hypophosphatasia during enzyme replacement therapy.
Brain Dev
; 41(8): 721-725, 2019 Sep.
Article
in En
| MEDLINE
| ID: mdl-31000369
ABSTRACT
Hypophosphatasia (HPP) is a rare disorder caused by low serum tissue non-specific alkaline phosphatase (ALP) activity due to hypomorphic mutations in the ALPL gene. HPP is characterized by defective bone mineralization. It frequently accompanies pyridoxine-responsive seizures. Because alkaline phosphatase change pyridoxal 5' phosphate (PLP) into pyridoxal (PL), which can cross the blood brain barrier and regulates inhibitory neurotransmitter gamma-aminobutyric acid. The female patient was born at a gestational age of 37â¯weeks 2â¯days. She presented severe respiratory disorder due to extreme thoracic hypoplasia. With the extremely low serum ALP value (14â¯IU/L), she was clinically diagnosed as HPP. The diagnosis was confirmed with genetic testing. On day1, the subclinical seizures were detected by aEEG. Together with enzyme replacement therapy by asfotase alfa, pyridoxine hydrochloride was administered, then the seizures were rapidly controlled. While confirming that there was no seizure by aEEG monitoring, pyridoxine hydrochloride was gradually discontinued after 1â¯month. Before administration of pyridoxine hydrochloride, PL was extremely low (4.7â¯nM) and PLP was increased (1083â¯nM). After the withdrawal, PL was increased to 84.9â¯nM only by enzyme replacement. Monitoring with aEEG enabled early intervention for pyridoxine responsive seizures. Confirming increased serum PL concentration is a prudent step in determining when to reduce or discontinue pyridoxine hydrochloride during enzyme replacement therapy.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Enzyme Replacement Therapy
/
Hypophosphatasia
Type of study:
Diagnostic_studies
Limits:
Female
/
Humans
/
Newborn
Language:
En
Journal:
Brain Dev
Year:
2019
Document type:
Article
Affiliation country: