此計劃的目的為尋找在未知原因的原發性B
細胞免疫缺陷病童的致病機轉是否為p110δ
基因突變所造成。但因根據外國資料, 原發
性B 細胞免疫缺陷的病童大部(約85%)為
Btk 基因突變所引起, 所以應須先行檢查Btk
基因； 不過, 因為目前台灣尚未有方便且可
靠的分子生物學方法來在原發B 細胞免疫缺
陷病童中確定診斷為XLA 疾病﹐也無XLA
病童的Btk 基因突變型本土資料。在國科會
補助下(NSC91-2314-13-002-189)﹐我們已建
立用genomic DNA-PCR and direct sequencing
的方法來從患有原發B 細胞免疫缺陷疾病的
病童中篩檢及確定其Btk 基因突變位置及多
型式從而來證實診斷為XLA 疾病。目前, 從
所篩檢病童中, 已成功確立4 個病童其Btk
基因突變位置及型式以及其家族的基因篩
檢。 同時, 亦已建立用RT-PCR and direct
sequencing 的方法來篩檢在Btk 基因檢查確
定無突變但仍不知原因的原發B 細胞免疫缺
陷病童的PI3 kinase p110δ基因是否有多型
性及突變以證實p110δ基因的突變可能是某
些未知原因的原發性B 細胞免疫缺陷的致病
機轉。目前, 在1 位病人發現其p110δ基因
有一整段Exon14 刪除。這段被刪除的基因
位於PI3 kinase 的accessory domain, 它在
PI3 和 PI4-kinase 是conserved 的,其功能為受
脢質的呈現。This study is to explore the possibility that
some patients with defects in B-cell
immunodeficiency of unknown etiology might
have mutations in PI3 kinase p110δ. Although,
according to the foreign data, the majority of
primary B-cell immunodeficiency (about 85%)
is due to Btk mutation. We need to exclude the
possibility of Btk gene mutation before we
check the p110δgene. However, at present,
there is still no convenient and reliable
molecular method for definite diagnosis of
XLA in patients with primary B-cell
immunodeficiency in Taiwan. There is no Btk
gene mutation and polymorphism data for
Taiwanese XLA patients, either. Under this
grant support of NSC (NSC91-2314-13-002-
189), we have established the methods to screen
the patients with primary B-cell defect by
genomic DNA-PCR and direct sequencing
analysis to identify the Btk gene mutations and
then establish the diagnosis of the XLA patients.
Until now, we have already successfully
identified 4 patients of primary B-cell
immunodeficiency with Btk gene mutation and
screened their family members. We also have
established the RT-PCR and direct sequencing
methods to screen the potential p110 δ gene
polymorphism and mutation in the remaining
primary B-cell immunodeficiency patients
without Btk mutations. Until now, we have
identified one patient with 2 different sizes of
his 3rd PCR amplified fragment. After cloning
and comparison with human p110δsequence,
the nucleotides 2,007-2,150 were completely
missed in the shorter band. These missed
nucleotides coded for the entire Exon 14(inreading
frame deletion). The missed Exon 14 is
located in PI3K accessory domain which is
conserved in all PI3 and PI4-kinase with the
function for substrate presentation
