Deletions of the long arm of chromosome 6: two new cases and review of the literature.

Seven terminal deletions and four interstitial deletions of 6q have been reported. We present the clinical and cytogenetic findings of these cases and of two new patients with different interstitial deletions of 6q. Although there are too few cases of interstitial deletions to identify one or more clinical syndromes associated with monosomies of the more proximal regions of 6q, a terminal 6q deletion syndrome is proposed. Its major components are microcephaly with mental retardation, strabismus, apparently low-set malformed ears, a broad nasal bridge, micrognathia, apparently short neck, congenital heart defect, abnormal palmar creases, and various hand abnormalities.