Ring chromosome 21 in a phenotypically normal but infertile man

Abstract

Analysis of the karyotype of an azoospermic 27‐year‐old man, without any dysmorphism, showed the presence of a ring chromosome 21.

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].…”

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

“…The FISH analysis confirmed the telomere deletion and the ring breakpoint in band 21q22. To investigate the ring chromosome 21 mosaicism, a buccal smear analysis was performed using FISH with the same probes and confirmed the mosaic as mos45,XY,À21 [5]/46,XY,r(21)[88]/ 46,XY [7], but clone proportions slightly differed.…”

“…When inherited, transmission frequently involves the mother (1), and in that particular case, parenthood is possible. But in the man, it is frequently associated with severe failure of spermatogenesis leading to azoospermia, cryptozoospermia, or oligospermia (5)(6)(7). Meiotic studies of an azoospermic male with r(21) indicated a failure of chromosome 21 pairing and a spermatogenesis arrest during the first meiotic division (8).…”

Ring chromosome 21 and reproductive pattern: a familial case and review of the literature

“…An infertile female with an otherwise normal phenotype was found to have a mos 46,XX, r(21)/45,XX, À21/46,XX, dic r (21) [94%, 4%, 2%]. The ring was inherited from her phenotypically normal mother.…”

“…Ring 21 [r (21)] is a quite rare finding. An infertile female with an otherwise normal phenotype was found to have a mos 46,XX, r(21)/45,XX, À21/46,XX, dic r (21) [94%, 4%, 2%].…”