Glu274Lys/Gly309Arg mutation of the tissue-nonspecific alkaline phosphatase gene in neonatal hypophosphatasia associated with convulsions.
We describe a patient diagnosed with lethal perinatal hypophosphatasia with a unique clinical presentation of convulsions that responded to vitamin B6. Genomic DNA sequence analysis of the tissue-nonspecific alkaline phosphatase (TNSALP) gene revealed two missense mutations: a G-to-A transition resulting in a Glu to Lys at codon 274 (E274K), and a G-to-C transversion resulting in a Gly to Arg at codon 309 (G309R). The first mutation was maternally transmitted and was previously characterized as a moderate one, whereas the latter was paternally transmitted and has not been previously reported. Phenotype/genotype correlation indicates that G309R is a deleterious mutation that can lead to seizures and a lethal outcome, as was demonstrated in our patient.
Litmanovitz
Department of Neonatology, Meir Medical Center, Kfar Saba Israel. falitman@netvision.net.il
Reish
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O
Dolfin
T
T
Arnon
S
S
Regev
R
R
Grinshpan
G
G
Yamazaki
M
M
Ozono
K
K
D000469:Alkaline Phosphatase / Q000235:genetics*; D001120:Arginine / Q000235:genetics; D005260:Female; D018698:Glutamic Acid / Q000235:genetics; D006801:Humans; D007014:Hypophosphatasia / Q000150:complications / Q000201:enzymology* / Q000235:genetics; D007231:Infant, Newborn; D008239:Lysine / Q000235:genetics; D020125:Mutation, Missense; D012640:Seizures / Q000150:complications / Q000201:enzymology* / Q000235:genetics
D018698:Glutamic Acid; D001120:Arginine; D000469:Alkaline Phosphatase; D008239:Lysine