We report on three cases with a cytogenetically identical ring chromosome containing euchromatin from the long arm of chromosome 1 (r[::p11.1→q21.1::]). Two cases were newborn males (Cases 1 and 2) and the third one was prenatally identified as female (Case 3). Mosaicism was present in all three cases in different degrees, i.e. 48%, 25% and 14% of the cells, respectively. Clinical signs and symptoms vary between the three cases.
The results of our three cases are compared with those from the literature.
aCentro de Investigación sobre Anomalías Congénitas (CIAC), Instituto de Salud Carlos III, Madrid, Spain
bInstitute of Human Genetics and Anthropology, Jena, Germany
cHospital de Leganés, Madrid, Spain
dInstitute of Human Genetics, Charité, Campus Virchow, Berlin, Germany
ePractice of Clinical Genetics, Düsseldorf, Germany
fEstudio Colaborativo Español de Malformaciones Congénitas (ECEMC), Dpto de Farmacología, Facultad de Medicina, Universidad Complutense de Madrid, Spain
Correspondence and requests for reprints to Laura Rodríguez, CIAC, Sinesio Delgado 6, 28029, Madrid, Spain
Tel: +34 91 3877800 ext. 2424; e-mail: email@example.com
Received 20 January 2005 Accepted 30 June 2005