Single-Nucleotide Polymorphism Array-Based Characterization of Ring Chromosome 18

2012

Objective To study genotype–phenotype correlation of ring chromosome 18 [r(18)] in 9 patients with 46,XN karyotype. Study design In 9 patients with a de novo 46,XN,r(18) karyotype (7 females, 2 males), we performed high-resolution single-nucleotide polymorphism array analysis (Illumina Human Omni1-QuadV1 array in 6 patients, Affymetrix 6.0 array in 3 patients), investigation of parental origin, and genotype–phenotype correlation. Results No breakpoint was recurrent. Single metaphases with loss of the ring, double rings, or secondarily rearranged rings were found in some cases, but true mosaicism was present in none of these cases. In 3 patients, additional duplications in 18p (of 1.4 Mb, 2 …