Ring-G Chromosome, a New G-Deletion Syndrome?

Abstract

DELETION of part of a G-group chromosome causes a syndrome,^1,2 which has been termed "antimongolism,"^3,4 because some of the phenotypic features appear antithetical to those observed in the G-trisomy syndrome of mongolism (Down's syndrome). This paper describes a patient with multiple anomalies and mental retardation associated with a ring and hence a deleted G chromosome. The phenotype of this patient is sufficiently similar to that of another patient with a G-chromosomal deletion 5 and different from "antimongolism" to suggest a new G-deletion syndrome. In our case no genetic locus could be assigned to the deleted segment, but four loci were excluded from such assignment. Report of a Case Labor and delivery of the patient, a girl born on Nov 17, 1964, were normal. Her birth weight was 2.98 kg (6.57 lb). Shortly after birth she was noted to have bilateral ptosis of the eyelids. At 15 months of