Cytogenetic analysis and phenotype location analysis on the karyotype of a ring chromosome 21 syndrome / 中华医学遗传学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To search the forming cause and the correlation between the clinical phenotype and chromosome band by the cytogenetic analysis on a case of ring chromosome 21 syndrome.</p><p><b>METHODS</b>Identification and location of 21 ring chromosome were performed with the G-banding, C-banding, N-banding, high-resolution banding and fluorescence in situ hybridization (FISH) techniques.</p><p><b>RESULTS</b>It was found that the karyotypes of the patient's parents are normal. The patient's karyotype is 46,XY, r(21)[91]/46,XY,r(21;21)(p11q22.3;p11q22.3) [5]/45,XY,-21[4].</p><p><b>CONCLUSION</b>The clinical phenotype of ring chromosome 21 syndrome is related to the deletion of distal segment of 21q, and the abnormal sexual development of male is related with the deletion of 21q22.3.</p>