Partial Trisomy of 7q: Case Report and Literature Review

Abstract

This case describes a boy with pure partial trisomy of the long arm of chromosome 7. The only prenatal finding on the boy was cerebral ventricular enlargement. After birth, mild facial dysmorphic features and cardiac malformations (pulmonary valve dysplasia, interatrial and interventricular septal defects) were detected. The boy developed severe psychomotor retardation, failure to thrive, and poor interaction with the environment. Focal seizures occurred in the neonatal period. Left frontotemporal abnormalities were observed in the subsequent electroencephalograms. An area of subependymal nodular heterotopia in the right frontal region was detected. Eighteen cases of 7q pure trisomy have been described in the literature over the years. The present study confirms that, in 7q trisomy cases, there are several common, yet nonspecific, features: macrocephaly, frontal bossing, failure to thrive, psychomotor delay, low-set ears, short neck, and genital-urinary tract abnormalities. Shortened life span seems associated only with duplication of the entire arm, and correlation phenotype-genotype seems questionable.