Protein and Genetic Analysis of Bruton's Tyrosine Kinase(Btk) in Three Korean X-linked Agammaglobulinemia(XLA) Families |
Eun-Kyeong Jo1, Chang-Hwa Song1, Jeong-Kyu Park1, Oh Kyung Lee2, Dong-Soo Kim1 |
1Department of Microbiology, College of Medicine, Chungnam National University, Taejon, Korea 1Department of Pediatrics, College of Medicine, Yonsei University, Seoul, Korea 2Department of Pediatrics, College of Medicine, Chungnam National University, Taejon, Korea |
X-관련성 범저감마글로불린혈증 3가족의 Bruton's Tyrosine Kinase 단백질 발현 및 유전자 변이 분석 |
조은경1, 송창화1, 박정규1, 이재호2, 김동수1 |
1충남대학교 의과대학 미생물학교실 1연세대학교 의과대학 소아과학교실 2충남대학교 의과대학 소아과학교실 |
Correspondence:
Dong-Soo Kim, Email: dskim6634@yumc.yonsei.ac.kr |
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Abstract |
Purpose : Mutations in the Bruton' s tyrosine kinase(Btk) gene are responsible for X-linked agammaglobulinemia(
XLA), an immunodeficiency caused by a block in B cell differentiation. In this
report we characterize the protein expression and genetic mutations of Btk in four Korean patients
with three unrelated XLA families.
Methods : The resulting Btk proteins were characterized by a flow cytometry and the mutations
were analyzed using single strand conformation polymorphism(SSCP) and direct sequencing.
Results : Two deletions, including one novel genetic alteration, and one splicing error, were found
in these three XLA families. Along with the identification of mutations, Btk protein analysis using
flow cytometry clearly showed cellular mosaicism in monocytes from five obligate carriers,
findings consistent with those by SSCP. We attempted to determine the origin of mutation in an
XLA family with a novel 4-bp deletion of exon eight, suggesting a germline mutation in this
family. In addition, we found some clinical heterogeneities in the affected brothers with the same
gene mutation.
Conclusion : These identified genetic alterations provided valuable clues to the pathogenesis of
XLA in Korea. The flow cytometric analysis is suggested as a useful tool for rapid detection of
XLA patients and carriers. |
Key Words:
Bruton' s tyrosine kinase, Mutation, X-linked agammaglobulinemia, Flow cytometry, Carrier detection |
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