Velo-cardio-facial syndrome. Intrafamilial variability of the phenotype
S. D. McLean, H. M. Saal, N. B. Spinner, B. S. Emanuel and D. A. Driscoll
Academy of Health Sciences, Fort Sam Houston, Tex.
We describe a mother and son with velo-cardio-facial syndrome (VCFS) in
whom cytogenetic and DNA molecular studies demonstrate an interstitial
deletion of the long arm of chromosome 22. Although these two individuals
manifest the typical facial and cognitive features of VCFS, they are
discordant for the cardiovascular and palatal anomalies, which are seminal
manifestations of the disorder. Previously, this degree of phenotypic
variability had not been well appreciated within a single family
segregating the VCFS deletion. A review of other familial cases of VCFS
suggests that the family described in this article is not atypical. Because
a microdeletion would be expected to be inherited without alteration within
individual families, the phenotypic variability observed in these families
appears to be an intrinsic quality of the syndrome and not wholly due to
genetic heterogeneity.
