Impact of Phospholipase A2 group IIa gene polymorphism on phenotypic features of patients with familial adenomatous polyposis.
OBJECTIVE
Phospholipase A2 Group IIa has been suggested to be a possible disease modifier gene in familial adenomatous polyposis. This investigation was designed to elucidate possible association between phospholipase A2 Group IIa polymorphism and phenotypes of patients with familial adenomatous polyposis.


METHODS
Phospholipase A2 Group IIa was examined by polymerase chain reaction-based single strand conformation polymorphism and direct sequencing in 55 patients from 45 families with familial adenomatous polyposis. The patients were examined by gastroduodenoscopy plus biopsy with respect to fundic gland polyposis and gastroduodenal adenomas. Helicobacter pylori status was determined by rapid urease test. Contributions of genetic alteration and Helicobacter pylori infection to intestinal and extraintestinal lesions were investigated.


RESULTS
Four types of single nucleotide polymorphism were found in exon 3 of phospholipase A2 Group IIa, among which single nucleotide polymorphism in codon 32 was the most frequent. The prevalence of fundic gland polyposis was higher in patients positive for single nucleotide polymorphism of phospholipase A2 Group IIa than those negative for single nucleotide polymorphism (61 vs. 33 percent; P < 0.05). In contrast, positive rate of Helicobacter pylori infection was lower in the former than in the latter (22 vs. 52 percent; P < 0.05). The prevalence of the other phenotypes was not different significantly. Logistic regression analysis revealed a possibility toward single nucleotide polymorphism of phospholipase A2 Group IIa as an independent risk factor for fundic gland polyposis (95 percent confidence interval, 00.9-14.3; P = 0.06).


CONCLUSIONS
Phospholipase A2 Group IIa may be a modifier gene for fundic gland polyposis in patients with familial adenomatous polyposis.
Yanaru-Fujisawa
Ritsuko
R
Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Fukuoka, Japan. yritsuko@intmed2.med.kyushu-u.ac.jp
Matsumoto
Takayuki
T
Kukita
Yoji
Y
Nakamura
Shotaro
S
Yao
Takashi
T
Hayashi
Kenshi
K
Iida
Mitsuo
M
D011125:Adenomatous Polyposis Coli / Q000201:enzymology* / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D002648:Child; D005260:Female; D017491:Genes, APC; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational