ACTN1 mutations cause congenital macrothrombocytopenia.

American journal of human genetics (2013-02-26)
Shinji Kunishima, Yusuke Okuno, Kenichi Yoshida, Yuichi Shiraishi, Masashi Sanada, Hideki Muramatsu, Kenichi Chiba, Hiroko Tanaka, Koji Miyazaki, Michio Sakai, Masatoshi Ohtake, Ryoji Kobayashi, Akihiro Iguchi, Gen Niimi, Makoto Otsu, Yoshiyuki Takahashi, Satoru Miyano, Hidehiko Saito, Seiji Kojima, Seishi Ogawa

Congenital macrothrombocytopenia (CMTP) is a heterogeneous group of rare platelet disorders characterized by a congenital reduction of platelet counts and abnormally large platelets, for which CMTP-causing mutations are only found in approximately half the cases. We herein performed whole-exome sequencing and targeted Sanger sequencing to identify mutations that cause CMTP, in which a dominant mode of transmission had been suspected but for which no known responsible mutations have been documented. In 13 Japanese CMTP-affected pedigrees, we identified six (46%) affected by ACTN1 variants cosegregating with CMTP. In the entire cohort, ACNT1 variants accounted for 5.5% of the dominant forms of CMTP cases and represented the fourth most common cause in Japanese individuals. Individuals with ACTN1 variants presented with moderate macrothrombocytopenia with anisocytosis but were either asymptomatic or had only a modest bleeding tendency. ACTN1 encodes α-actinin-1, a member of the actin-crosslinking protein superfamily that participates in the organization of the cytoskeleton. In vitro transfection experiments in Chinese hamster ovary cells demonstrated that altered α-actinin-1 disrupted the normal actin-based cytoskeletal structure. Moreover, transduction of mouse fetal liver-derived megakaryocytes with disease-associated ACTN1 variants caused a disorganized actin-based cytoskeleton in megakaryocytes, resulting in the production of abnormally large proplatelet tips, which were reduced in number. Our findings provide an insight into the pathogenesis of CMTP.

Product Number
Product Description

Anti-ACTN1 antibody produced in rabbit, Prestige Antibodies® Powered by Atlas Antibodies, affinity isolated antibody, buffered aqueous glycerol solution
α-Actinin from chicken gizzard, ~80% α-actinin basis (SDS-PAGE), ammonium sulfate suspension