Formation of a familial ring chromosome 18 investigated by SNP-array analysis

摘要

Three years ago in the Journal some of us reported on a 23-year-old man with multiple congenital anomalies, intellectual disability, and a 46,XY,r(18)(::pll->q21::)[75]/46,XY[25] karyotype. This finding was proven by conventional karyo typing (G-banding) and FISH with the alphoid 18 centromere probe D18Z1, BAC 248E24 (18q21.33), CEPH YAC957g7 (D18S466/D18S1092/D18S61; 18q22.1-q22.2), and CEPHYAC968f4 (D18S488; 18q22.3), respectively [Balci et al, 2011]. His mother, who was healthy and of normal intelligence, showed a 47,XX,+r(18)(::pll->q21::)[10]/46, XX[90] karyotype. All investigations had been performed on lymphocytes. The father, who was a first cousin of his wife, and the sister of our patient showed normal karyotypes. The parents of the mother were not related.