Detection of a new mutation (G1253T) of iduronate-2-sulfatase gene for the patient with mucopolysaccharidosis type II / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the mutations of iduronate-2-sulfatase (IDS) gene in mucopolysaccharidosis type II patients.</p><p><b>METHODS</b>PCR-SSCP analysis was applied to detect the common mutations in the exons 2, 3, 5, 7, 8, 9 in IDS-gene of the patient. DNA sequencing and PCR-RFLP were applied to analyze the mutation detected by PCR-SSCP.</p><p><b>RESULTS</b>A new mutation(1253G-->T) of exon 7 of the IDS gene was found by PCR-SSCP and DNA sequencing in the patient, The PCR-restriction enzyme digestion showed that enzyme digestion location appeared in the patient and his mother, which verified the results of sequencing analysis.</p><p><b>CONCLUSION</b>The mutation of patient with MPSII could be detected effectively and quickly by the applications of PCR-SSCP, DNA sequencing and PCR-restriction enzyme digestion analysis, and the new mutation thus detected is necessary for the prenatal diagnosis of the pedigree.</p>

Diagnosing achondroplasia by single cell nested-PCR / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To research on the reliability of diagnosing achondroplasia (ACH) on single cell level and to provide a basis for preimplantation genetic diagnosis(PGD).</p><p><b>METHODS</b>The high-frequency mutation region G380R of fibroblast growth factor receptor 3(FGFR3) gene was amplified by nested-PCR with single lymphocyte and single blastomere. The products of PCR were digested by restriction enzyme Bfm I, then the digested products were detected by 10% polyacrylamida gel electrophoresis(PAGE).</p><p><b>RESULTS</b>The amplification success rate, allele dropout rate and correct diagnosis rate of single lymphocyte's PCR were 90.4%, 8.2% and 91.8%,respectively. The amplification success rate of single blastomere was 75.4%.</p><p><b>CONCLUSION</b>The diagnosis of ACH by single cell nested-PCR is comparatively stable and reliable.</p>

46,XY female sex reversal patient with a novel point mutation in the coding sequence of the SRY gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the molecular mechanism of a Chinese patient with 46, XY sex reversal.</p><p><b>METHODS</b>DNA fragments of the SRY gene from the typical XY female sex reversal patient and her father were amplified by polymerase chain reaction (PCR). The amplified PCR fragments were cloned into the pUCm-T vector, and direct sequencing was carried out on an ABI 377-3 automated DNA sequencer to detect the mutation. PCR-restriction enzyme digestion was applied to detect the results of DNA sequencing.</p><p><b>RESULTS</b>A novel mutation of the SRY gene was identified in the XY sex reversal patient of this study. A T is replaced by an A in codon 129 at position +387, resulting in the replacement of the polar amino acid tyrosine (TAT) by the stop code (TAA) in the HMG-box, whereas her father was proved to have the wild-type sequence. Because the mutation introduced an enzyme site of MaeIII, the PCR-restrict enzyme digestion showed that there were three bands (131 bp,231 bp and 247 bp) in the patient, whereas two bands (131 bp and 478 bp) in normal man. It verified the results of sequencing analysis. The results after searching the Human Gene Mutation Database showed that this mutation was not described before and should be a new mutation.</p><p><b>CONCLUSION</b>The novel mutation in SRY gene has provided valuable information for the understanding of molecular mechanism of the patient with 46,XY female sex reversal.</p>