ABSTRACT
Objective To screen the sequence of fibroblast growth factor receptor 3 (FGFR3) genes in children with dys-chondroplasia and their family members for searching the mutations. Methods The sequence of exon 10 and exon 13 in muta-tion hot spot region of FGFR3 gene in seven families was analyzed using polymerase chain reaction (PCR) and DNA sequenc-ing technology. Results The c.1138G>A missense mutation in exon 10 was found in 4 probands who were diagnosed as achon-droplasia (ACH), while this mutation was absent in their parents. The c.1620C>A missense mutation in exon 13 was found in one girl and her mother who both were diagnosed as hypochondroplasia (HCH) with mild symptoms. Neither mutation men-tioned above was found in the other two probands. Conclusions Through detecting the mutation in exon 10, exon 13 of FGFR3 gene, most patients of ACH or HCH can be finally diagnosed. However, it is necessary to perform the mutation screening on the other zones of FGFR3 gene and on other related genes for a few cases.
ABSTRACT
Objective To investigate the clinical features and pathogenesis of severe congenital neutropenia (SCN) by detecting the gene mutation of a SCN patient suspected by clinical diagnosis. Methods The intravenous anticoagulant and clin-ical data and laboratory results of this child were collected;the phagocyte and oxidation function of neutrophils were evaluated by flow cytometry;ELANE, HAX1, WAS, GFI1, CSF3R and CXCR4 genes were screened by PCR amplification and sequencing. Results The neutrophil function of this patient was normal; sequencing results revealed no mutation occurred in ELANE, HAX1, WAS, GFI1, CSF3R and CXCR4;and granulocyte colony-stimulating factor (G-CSF) can obviously enhance the level of neutrophils. Conclusion SCN is a kind of genetic heterogeneity syndrome associated with multiple gene mutations, gene diag-nosis will contribute to understanding of the pathogenesis of the disease and provide theoretical basis for treatment. Though more and more pathogenic genes were found to be connected with SCN, the cases of unknown mutation still account for a large proportion of this disease.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect and mechanism of high dose Vitamin B3 on granulopoiesis in normal rat.</p><p><b>METHODS</b>Twenty one healthy SD rats were randomly divided into three groups: the Vitamin B3 group (Vit B3 500 mg·kg⁻¹·d⁻¹, × 7 d), the rhG-CSF group (rhG-CSF 25 μg·kg⁻¹·d⁻¹, × 7 d) and the normal saline group (2 ml/d, × 7 d). The peripheral blood cell counts were analyzed by automatic blood cell counter before (day 0) treatment, the third day (day 3) and the seventh day (day 7) after administration of drugs, respectively. The concentration of serum nicotinamide adenine dinucleotide (NAD⁺) level was measured by enzymatic cycling assay before and after drugs treatment. The expressions of G-CSF, G-CSFR, SIRT1, C/EBPα, C/EBPβ, C/EBPε and NAMPT mRNA were detected by reverse transcription real-time fluorescent quantitative PCR.</p><p><b>RESULTS</b>The neutrophil counts increased significantly after 7 days of Vitamin B3 and rhG-CSF treatment compared with that of control group [(1.64 ± 0.19) × 10⁹/L, (1.88 ± 0.37)× 10⁹/L vs (0.86 ± 0.18) × 10⁹/L, P<0.01]; the level of serum NAD⁺ increased significantly [(0.96 ± 0.08) nmol/L, (0.65 ± 0.12) nmol/L vs (0.36 ± 0.15) nmol/L, P<0.01]; the expression of G-CSF, G-CSFR, SIRT1, C/EBPα, C/EBPε and NAMPT mRNA in bone marrow mononuclear cells were increased significantly compared with that of control group (P<0.01).</p><p><b>CONCLUSION</b>High dose of Vitamin B3 may play an important role in increasing absolute neutrophil count in healthy rat under steady state, and the mechanism may be dependent on NAMPT-NAD⁺-SIRT1 signaling pathways.</p>