{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,12]],"date-time":"2026-05-12T22:33:36Z","timestamp":1778625216200,"version":"3.51.4"},"reference-count":19,"publisher":"Wiley","issue":"3","license":[{"start":{"date-parts":[[2005,12,14]],"date-time":"2005-12-14T00:00:00Z","timestamp":1134518400000},"content-version":"vor","delay-in-days":3941,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Prenatal Diagnosis"],"published-print":{"date-parts":[[1995,3]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Ring chromosome 21 is a rare chromosome anomaly often associated with mental retardation and dysmorphic features. Less commonly, the ring chromosome can be familial and associated with a normal phenotype. Phenotypically normal female carriers, however, are at increased risk of having children with Down syndrome, mosaic monosomy 21, and variable duplication or deletion of chromosome 21. Because of the relative mitotic and meiotic instability of ring chromosomes, abnormal cytogenetic findings encountered during prenatal diagnosis may not reflect the true genetic status of the fetus. This is a report of a phenotypically normal female carrier of a familial ring 21 chromosome. Prenatal diagnosis on her twin pregnancy revealed a mosaic 46,XX,r(21)(p13;q22) (77 per cent)\/45,XX, \u2013 21 in one fetus and a normal male karyotype in the second. The pregnancy was carried to term. Both infants are completely normal, with a non\u2010mosaic ring 21 karyotype from the lymphocytes of one twin. The diagnostic uncertainty and problematic genetic counselling related to fetal cytogenetic abnormalities are the subjects of this report.<\/jats:p>","DOI":"10.1002\/pd.1970150310","type":"journal-article","created":{"date-parts":[[2007,3,4]],"date-time":"2007-03-04T10:35:43Z","timestamp":1173004543000},"page":"269-273","source":"Crossref","is-referenced-by-count":16,"title":["Prenatal diagnosis of familial ring 21 chromosome"],"prefix":"10.1002","volume":"15","author":[{"given":"A. R.","family":"Melnyk","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"I.","family":"Ahmed","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J. C.","family":"Taylor","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2005,12,14]]},"reference":[{"key":"e_1_2_1_2_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1399-0004.1987.tb02766.x"},{"key":"e_1_2_1_3_1","first-page":"161","volume-title":"The ACT Cytogenetics Manual","author":"Barch M. 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Iugosl."}],"container-title":["Prenatal Diagnosis"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fpd.1970150310","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/pd.1970150310","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,26]],"date-time":"2023-10-26T19:09:44Z","timestamp":1698347384000},"score":1,"resource":{"primary":{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/10.1002\/pd.1970150310"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1995,3]]},"references-count":19,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1995,3]]}},"alternative-id":["10.1002\/pd.1970150310"],"URL":"https:\/\/doi.org\/10.1002\/pd.1970150310","archive":["Portico"],"relation":{},"ISSN":["0197-3851","1097-0223"],"issn-type":[{"value":"0197-3851","type":"print"},{"value":"1097-0223","type":"electronic"}],"subject":[],"published":{"date-parts":[[1995,3]]}}}