Single nucleotide polymorphisms of β-globin gene in β-thalassaemia patients / 中国实验血液学杂志

This study was aimed to analyze the β-globin gene sequence and single nucleotide polymorphisms of the β-globin gene in β-thalassaemia patients from Shenzhen area, and to explore linkage relationships between β-globin gene mutations and single nucleotide polymorphisms. Genomic DNA was extracted from peripheral leukocytes in 125 β-thalassaemia patients from Shenzhen population. β-globin gene was amplified by polymerase chain reaction, mutations and single nucleotide polymorphisms in the β-globin gene were determined by DNA sequencing. The results indicated 10 types of mutation and 12 single nucleotide polymorphism loci were found in the β-globin gene of 114 β-thalassaemia patients. Linkage disequilibrium between mutations and single nucleotide polymorphisms was found in 6 loci including 6 haplotypes among these single nucleotide polymorphism loci in the β-globin gene. It is concluded that a number of single nucleotide polymorphisms is found in the β-globin gene, where an average of one single nucleotide polymorphism every 230 bp there is. Linkage disequilibrium occurs between β-thalassaemia mutations and some haplotypes in single nucleotide polymorphism loci. This study may be helpful to gene diagnosis for β-thalassaemia patients.

Different splice of the calpain 3 gene in human skeletal muscle tissue and white blood cells / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the splice variants of the calpain 3 gene existing in human skeletal muscle tissue and white blood cells, and to explore the feasibility of gene diagnosis using CAPN3 mRNA extracted from peripheral leukocytes.</p><p><b>METHODS</b>Total RNA was extracted from peripheral blood and skeletal muscle tissue in healthy individuals. CAPN3 cDNAs were determined by reverse transcriptase polymerase chain reaction and DNA sequencing. CAPN3 cDNAs from peripheral leukocytes were compared with sequences obtained from skeletal muscle tissue.</p><p><b>RESULTS</b>RT-PCR and DNA sequencing showed that the CAPN3 cDNAs comprised 24 exons in human skeletal muscle tissue, while the number of exons was 23 in white blood cells. Exon 15 was spliced out in human white blood cells.</p><p><b>CONCLUSION</b>Splice variants exist in human skeletal muscle tissue and white blood cells. Gene diagnosis may omit the mutations of exon 15 using mRNA extracted from peripheral leukocytes. These findings suggest that mutation analysis of the CAPN3 cDNA should use skeletal muscle tissue as materials instead of peripheral blood.</p>

Changes of serum creatine kinase levels in children with Duchenne muscular dystrophy / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Duchenne muscular dystrophy (DMD) usually occurs prior to 3 years old. The value of serum creatine kinase changes with clinical progression and age in patients with DMD. This study aimed to investigate the regularity in the changes of serum creatine kinase activities in children with DMD.</p><p><b>METHODS</b>Peripheral blood samples were obtained from 40 children with DMD (ranged from 3-14 years). Serum creatine kinase levels were assayed by kinetic UV test.</p><p><b>RESULTS</b>Serum creatine kinase level in the 40 DMD patients (ranged from 2 595- 45 495 U/L) was remarkably higher than the reference value (35-174 U/L). The highest serum creatine kinase level (average: 27750-31173 U/L) was found in 3-5 years old patients. Afterwards, serum creatine kinase level decreased with clinical progression and age, with a yearly average rate of decline was 8.7%.</p><p><b>CONCLUSIONS</b>Serum creatine kinase level reaches a peak between 3 and 5 years old and then reduces with increasing age in children with DMD. The characteristic changes of serum creatine kinase are suspected to reflect the rate of muscle decay.</p>