Application of the Bgl II-Bln I dosage test to gene diagnosis of facioscapulohumeral muscular dystrophy 1A gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To increase the sensitivity and specificity of conventional gene diagnosis of facioscapulohumeral muscular dystrophy 1A(FSHD1A) by analyzing the distribution of translocation between chromosomes 4q35 and 10q26 in suspected FSHD cases.</p><p><b>METHODS</b>The Bgl II- Bln I dosage test was performed to detect translocation between chromosomes 4q35 and 10q26 in 7 cases of presymptomatic FSHD patients showing positive result in gene diagnosis and 5 cases of sporadic FSHD patients showing negative result in gene diagnosis. DNA samples were digested with Bgl II and Bln I, followed by agrose gel electrophoresis. Probe p13E-11 was labeled with alpha-(32) P dCTP, followed by Southern hybridization. Then the ratio between the chromosomes 4 and 10 derived signal intensities was judged and hence was made known whether there was interchromosomal translocation between chromosomes 4 and 10.</p><p><b>RESULTS</b>The Bgl II-Bln I dosage test revealed a translocation from chromosome 4q35 to 10q26 in one presymptomatic FSHD patient, thus indicating the result of gene diagnosis for her might be false positive. There was one translocation from chromosome 10q26 to 4q35 detected in one sporadic FSHD patient, indicating the result of gene diagnosis for her might be false negative. There were no translocations between chromosomes 4 and 10 in the other 10 cases.</p><p><b>CONCLUSION</b>The Bgl II-Bln I dosage test can detect the translocation between chromosomes 4q35 and 10q26. It can improve the accuracy of the conventional method for gene diagnosis of FSHD1A.</p>

Translocation between chromosomes 4q35 and 10q26 in facioscapulohumeral muscular dystrophy / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the distribution of translocation between chromosomes 4q35 and 10q26 in facioscapulohumeral muscular dystrophy (FSHD) patients and normal individuals.</p><p><b>METHODS</b>The Bgl II-Bln I dosage test was performed to study the distribution of translocation between chromosomes 4q35 and 10q26 in 70 cases of FSHD patients, 55 cases of kindred with FSHD, and 52 cases of normal controls.</p><p><b>RESULTS</b>(1) In normal individuals, the frequency of translocation between chromosomes 4q35 and 10q26 is 19.23%. The frequency of translocation from chromosome 4q35 to 10q26 and that from chromosome 10q26 to 4q35 are both 9.62%. (2) In the FSHD patients, the frequency of translocation between chromosomes 4q35 and 10q26 is 18.57%. The frequency of translocation from chromosome 4q35 to 10q26 and that from chromosome 10q26 to 4q35 are 12.86% and 5.71% respectively.</p><p><b>CONCLUSIONS</b>The translocation between chromosomes 4q35 and 10q26 was frequently observed in both normal Chinese population and FSHD patients. No significant difference was observed between them.</p>