title: 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.
mesh_terms: D000328:Adult; D002869:Chromosome Aberrations; D002904:Chromosomes, Human, 21-22 and Y; D006801:Humans; D007248:Infertility, Male / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D010375:Pedigree; D010641:Phenotype; D012303:Ring Chromosomes