Mutations in tropomyosin 4 underlie a rare form of human macrothrombocytopenia.
J Clin Invest
; 127(3): 814-829, 2017 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-28134622
ABSTRACT
Platelets are anuclear cells that are essential for blood clotting. They are produced by large polyploid precursor cells called megakaryocytes. Previous genome-wide association studies in nearly 70,000 individuals indicated that single nucleotide variants (SNVs) in the gene encoding the actin cytoskeletal regulator tropomyosin 4 (TPM4) exert an effect on the count and volume of platelets. Platelet number and volume are independent risk factors for heart attack and stroke. Here, we have identified 2 unrelated families in the BRIDGE Bleeding and Platelet Disorders (BPD) collection who carry a TPM4 variant that causes truncation of the TPM4 protein and segregates with macrothrombocytopenia, a disorder characterized by low platelet count. N-Ethyl-N-nitrosourea-induced (ENU-induced) missense mutations in Tpm4 or targeted inactivation of the Tpm4 locus led to gene dosage-dependent macrothrombocytopenia in mice. All other blood cell counts in Tpm4-deficient mice were normal. Insufficient TPM4 expression in human and mouse megakaryocytes resulted in a defect in the terminal stages of platelet production and had a mild effect on platelet function. Together, our findings demonstrate a nonredundant role for TPM4 in platelet biogenesis in humans and mice and reveal that truncating variants in TPM4 cause a previously undescribed dominant Mendelian platelet disorder.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Trombocitopenia
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Tropomiosina
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Plaquetas
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Mutação de Sentido Incorreto
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Genes Dominantes
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Doenças Genéticas Inatas
Tipo de estudo:
Prognostic_studies
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Risk_factors_studies
Limite:
Animals
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Humans
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Male
Idioma:
En
Revista:
J Clin Invest
Ano de publicação:
2017
Tipo de documento:
Article