Clinical, pathological, and genetic analysis of ten patients with MYH9-related disease.

MYH9-related disease (MYH9-RD) is an autosomal dominant disorder caused by mutations in the MYH9 gene. It is characterized by a triad of giant platelets, thrombocytopenia, and characteristic Döhle body-like granulocyte inclusions. In this study we report 10 unrelated patients with MYH9-RD in whom the following seven MYH9 gene mutations were found: W33R, p.Q1443_K1445dup, R702H, D1424N, E1841K, R1933X, and E1945X (the first two were novel mutations). The region of the MYH9 mutation determines in some regards the phenotype, but clinical expression can vary between individuals with the same mutation. The neutrophil inclusion bodies of two patients were too small to be detected, but could be found with immunofluorescence staining. Immunoblotting analysis revealed that the calculated NMMHC-IIA/ß-actin ratio for MYH9-RD neutrophils was 39% of normal controls. Kidney biopsy showed segmental glomerulosclerosis and NMMHC-IIA expression was decreased in podocytes. This disease is not as rare as originally thought. In any individual with persistent macrothrombocytopenia and no response to corticosteroids and immunosuppressive agents, even if neutrophil inclusions were inconspicuous in routine staining, MYH9-RD should be suspected.

[Clinical features and gene analyses of six patients with MYH9-related disease].

OBJECTIVE: To investigate clinical features and to identify gene mutations in six patients with nonmuscle myosin heavy chain 9 gene (MYH9)-related disease. METHODS: The platelet counts were measured using automated complete blood cell counter and manual manner. The size of platelets and inclusion bodies were observed under light microscopy. All the 40 exons and exon-intron boundaries of MYH9 gene were amplified by PCR and then DNA sequencing was performed. Restriction endonuclease analysis and polyacrylamide gel electrophoresis (PAGE) were used for polymorphism analysis. RESULTS: Six patients all shared the common features of thrombocytopenia with giant platelets and granulocyte inclusions. Four MYH9 gene mutations were found in the six patients: T97C (W33R) in exon 1, 4335Insert CAGAAGAAG (1445InsQKK) and G4269A (D1424N) in exon 30 and G5833T (E1945Stop) in exon 40. The former two were novel mutations which have not been reported in the literature. The results of restriction endonuclease analysis and PAGE could exclude the possibility of nucleotide polymorphisms. CONCLUSIONS: The MYH9 gene mutations were identified in six patients with MYH9 related disorders, and T97C (W33R) and 4335InsCAGAAGAAG (1445InsQKK) were novel mutations. MYH9 related disease should be considered in individuals with persistent thrombocytopenia which is non-responsive to corticosteroids and immuno-repressive agents.

[In vitro effects of hemocoagulase atrix and its effective components on blood coagulation of patients with bleeding disorders].

This study was aimed to investigate the pro coagulation effects of hemocoagulase atrix and its effective components (batroxobin and factor X activator) on plasma of normal subjects and patients with bleeding disorders and their mechanisms. Activated partial thromboplastin time (APTT) and prothrombin time (PT) were measured. The factor (F)X activation and thrombin generation were analyzed by using chromogenic substrate method. The results showed that the plasma APTT of normal subjects was shortened by hemocoagulase atrix, batroxobin and FX activator, and the effect of FX activator was found to be concentration-dependent (r = 0.889, P < 0.05). The prolonged APTT of plasma from patients with bleeding disorders could be corrected by hemocoagulase atrix, batroxobin and FX activator, but PT showed no great changes resulted from the treatments. FX activator could promote FX activation and thrombin generation, while neither hemocoagulase atrix nor batroxobin showed such abilities. It is concluded that hemocoagulase atrix promotes coagulation process, and corrects coagulation abnormalities in patients with bleeding disorders, its main component batroxobin directly acts on fibrinogen, and FX activator promotes thrombin generation through activating FX.

[Clinical and gene study of three pedigrees of phytosterolemia associated with macrothrombocytopenia and hemolysis].

OBJECTIVE: To study the clinical features and ABCG5/ABCG8 gene mutations of three pedigrees of phytosterolemia presented with macrothrombocytopenia and hemolysis. METHODS: Erythrocyte and platelet morphology were examined under light microscope. Plasma sterol levels were measured by high pressure/performance liquid chromatography method. All of ABCG5 and ABCG8 exons and intron-exon boundaries were directly sequenced to identify mutations, the corresponding gene mutation sites of three families members and healthy individuals were detected. RESULTS: All the patients presented macrothrombocytopenia, hemolysis, splenomegaly and xanthomas. The blood smears showed large platelets, some as large as erythrocytes, and abnormal erythrocyte shapes, such as stomatocytes. Plasma concentrations of phytosterols, especially sitosterol were markedly elevated (30 fold) in the affected patients. Four mutations were identified in these three pedigrees, ABCG5 C20896T (R446X) and A20883G, ABCG8 del43683-43724 and del1938C-1939G/ins1938T. The latter three were novel mutations reported for the first time. CONCLUSIONS: Phytosterolemia associated with macrothrombocytopenia and hemolysis is a new subtype of this disease. Plasma phytosterols and related gene analysis should be performed when ever an unexplained macrothrombocytopenia, especially combined with haemolysis or/and stomatocytosis.

[Genotype and phenotype analysis of congenital coagulator factor VII deficiency in four Chinese pedigrees].

OBJECTIVE: To investigate the clinical manifestation and gene mutation in four Chinese pedigrees with the congenital coagulation factor VII deficiency. METHODS: Prothrombin time (PT), activated partial thromboplastin time, thrombin time and plasma fibrinogen were measured using STAGO STA-R automatic coagulation analyzer, and the coagulation activity of factor VII (FVII:C) was determined by a PT-based one stage method, and factor VII antigen (FVII:Ag) level by a sandwich enzyme-linked immunoabsorbsent assay. All exons, exon-intron boundaries and 3',5'untranslated regions of the FVII gene from the genomic DNA of the probands and their families were amplified by PCR, and then sequenced. RESULTS: PT was significantly prolonged, and FVII:C and FVII:Ag were decreased and the following mutations were identified in the four probands: a homozygous transversion of 18041 T→G resulting in His408→Gln substitution in exon 8 in proband 1, a homozygous double nucleotide deletion, del CT (5078 - 5079) in exon 1 in proband 2, a double heterozygous of IVS6-1G→A and Gln426→stop in proband 3, and a double heterozygous of IVS6-1G→A and Arg364Gln in prohand 4. CONCLUSION: Two missense mutations, His408Gln, Arg364Gln and one nonsense, Gln426stop in the catalytic domain of FVII and one double nucleotide deletion, del CT (5078 - 5079) in exon 1 and one splicesome mutation, IVS6-1G→A in intron 6 were separately identified in four Chinese pedigrees with inherited coagulation factor VII deficiency. The Gln426stop and IVS6-1G→A were first identified in the world and the homozygous del CT (5078 - 5079) and His408Gln were first found in China.

[Analysis of clinical features and gene mutations in 6 patients with Wiskott-Aldrich syndrome].

OBJECTIVE: To investigate clinical features, laboratory alterations and gene mutations of 6 patients with Wiskott-Aldrich syndrome (WAS). METHODS: T lymphocyte subtypes were measured by flow cytometer. The routine blood tests including platelet count and mean platelet volume were performed by complete blood analyzer Sysmex XE2100. Serum immunoglobulin was measured by immunoturbidimetry. Mutations in WAS protein (WASP) gene (including all the exons and exon-intron boundaries and 3', 5' untranslation region) of 6 patients and their family members were identified by PCR and sequencing. RESULTS: The patients presented with petechiae, easy bruise, eczema, bloody diarrhea, recurrent infection and fever, and the clinical scores were 3 or 4. They were thrombocytopenia with smaller mean platelet volume, anemia and leukocytosis. Megakaryocyte number was normal or slightly increased in bone marrow. In the probands, the percentage of CD3+ T cells was decreased, the CD4+/CD8+ ratio was abnormal, while the fractions of CD19+ and CD16+ CD56+ cells were in normal range. In most of the patients, the serum levels of IgG and IgA were increased. Six mutations were identified in the patients, including 10250 C-->T, and five novel mutations: 6783 C-->G,10216-10221 Ins G, 9964 Del T,10192-10203 Del GCCTGCCGGGG and 10052-10059 del GCTACTG. The 6783 C-->G in exon 3 resulted in premature stop at Tyr102, and the remaining four mutations in exon 10 resulted in frame shift and premature stop. CONCLUSION: The main characteristics of these WAS patients were thrombocytopenia with smaller mean platelet volume and immunological disturbance. Their gene mutations were deletion, insertion or nonsense mutations. All the patients had been misdiagnosed as ITP, indicating the importance of differential diagnosis.