title: Familial transmission of a ring chromosome 21.
abstract: A ring chromosome 21 was found in a phenotypically normal mother and her son. The clinical findings in the son were bilateral retention of the testes and a slightly delayed puberty onset. Consequences of a ring formation of a chromosome 21 in phenotypically normal patients are presented and discussed, and the previously reported cases of familially transmitted G-group ring chromosomes are reviewed.
mesh_terms: D000293:Adolescent; D000328:Adult; D002869:Chromosome Aberrations / Q000235:genetics*; D025063:Chromosome Disorders; D002891:Chromosomes, Human, Pair 21 / Q000648:ultrastructure*; D003456:Cryptorchidism / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D010641:Phenotype; D011628:Puberty, Delayed / Q000235:genetics*; D012303:Ring Chromosomes