We report on a 14-year-old boy with ring chromosome 20. Clinical manifestations included postnatal growth retardation, epilepsy, microcephaly, behaviour disorder, minor facial anomalies, small sella turcica, possible partial growth hormone deficiency, and mental retardation. A decreased activity of enzyme carboxypeptidase-L/protective protein (CP/PP) in cultured fibroblasts was demonstrated in our patient and a patient with a karyotype 46,XY,-14, + der(14)t(14;20)(14pter----14q32.3::20q13.1----20qter)m at. This suggests possible assignment of the CP/PP gene to the distal segment of 20q.
Halal F, Chitayat D, Parikh H, Rosenblatt B, Tranchemontagne J, Vekemans M, Potier M (1992) Ring chromosome 20 and possible assignment of the structural gene encoding human carboxypeptidase-L to the distal segment of the long arm of chromosome 20 American Journal of Medicine Genet43: 576-9
Halal F, Chitayat D, Parikh H, Rosenblatt B, Tranchemontagne J, Vekemans M, Potier M (1992) American Journal of Medicine Genet43: 576-9