[Application of Bionano-DNA Full-Length Optical Mapping Technology in Genetic Diagnosis of Hemophilia A Carriers].

OBJECTIVE: To apply Bionano Saphyr visual full-length DNA optical mapping technology to the precise genetic diagnosis of hemophilia A carriers. METHODS: For 2 suspected F8 gene deficiency female carriers who could not be diagnosed by conventional next-generation sequencing technology, the full-length DNA optical mapping technology was used to detect and scan the sample X chromosome full-length visual haplotype characteristic map, which was compared with the normal haplotype. The gene structure variation information of the samples was obtained by compare with DNA atlas library. RESULTS: The average fluorescent marker length of the X chromosome DNA molecular where the F8 gene was located in the two samples was greater than 2.5 Mbp, and the average copy number was greater than 20×. After comparative analysis, one of the samples was a proximal inversion of intron 22 of the F8 gene, and another was an inversion of intron 22 accompanied by multiple deletions of large fragments. CONCLUSIONS: Bionano technology has a good detection rate for gene defects with large length and complex variation. In the absence of a proband or accurate genetic diagnosis results of the proband, the application of this technology to detect the heterozygous complex variant of the F8 gene is of great significance for the prenatal diagnosis and pre-pregnancy diagnosis of hemophilia carriers.

[Research Progress on the Mechanism of Tubulin in Megakaryopoiesis and Regulation of Platelet Count--Review].

Tubulin affects platelets count through the control of mitosis and the formation of pro-platelets during the maturation of megakaryoblast to platelets. Tubulin is involved in maintaining the integrity of platelet skeleton, and also participates in the change of platelet morphology during platelet activation. Some new anti-tumor drugs targeting cell mitosis are trying to reduce the effect on tubulin in order to reduce the side effect of drugs on platelet formation. In some patients with thrombocytopenia, the variation and polymorphism of the tubulin gene affect the structure of microtubule multimers, which leads to the decrease of platelet formation. This review summarized the latest progresses of tubulin in the regulation of megakaryopoiesis and thrombopoiesis.