Sperm chromosome analysis of an infertile patient with a 95% mosaic r(21) karyotype and normal phenotype

Azoospermia and ring chromosome 9—a case report

“…In total 84 % of cells contained the r(9) in the present case, which corresponds well with previous reports on r (12,15,21,22), in which 85-97 % of the autosomal ring chromosomes were found in relation to azoospermia [8,[20][21][22][23]. In contrast, some previous cases including fertile men with a lower degree of mosaicism (<50 %) have been described [24,25].…”

The normality of sperm in an infertile man with ring chromosome 15: a case report

“…This is the first report analyzing the chromosome status and fertilization capability of sperm obtained from an infertile patient with ring chromosome 15. These sperm did not contain ring chromosome 15 (Table 1), and the motile sperm that were selected for ICSI had a normal karyotype, which is consistent with previous study [19]. Furthermore, the fertilization and non-fertilization rates differed according to the aspect ratio and the short-axis length of the sperm heads (Tables 2 and 3).…”

“…These results may suggest that the vast majority of germ cells containing ring chromosome and/or other chromosomal defects may be eliminated during the course of spermatogenesis, which would eventually cause oligozoospermia [19,33]. In support of this idea, a previous study showed that a ring chromosome was unable to pair with a sister chromosome at meiotic division, and these meiotic cells were arrested during spermatogenesis [34].…”

“…Although few studies have reported on the characteristics of sperm from patients with ring chromosomes, to the best of our knowledge, only one study reported that sperm actually contained ring chromosome 21 (based on the results of FISH). In that report, the incidence of ring chromosome 21 among the sperm that were likely candidates for ICSI selection under an inverted microscope was 7.7% (6.5% carried ring chromosome 21 and 1.2% carried both the ring chromosome and a normal homologue) [19]. However, no studies have analyzed the fertilization capability or karyotype of sperm obtained from men carrying ring chromosome using ICSI.…”

“…fumiaki-itoi@kishokai.or.jp ejaculated sperm of a man with ring chromosome 21 for ICSI selection using fluorescence in situ hybridization (FISH) [19]. In addition, few studies have tested the fertilization capability or chromosome status of sperm collected from patients with ring chromosome for ICSI.…”