Interstitial duplication of 7(q22-->q34).

We report on a 3-year-old boy with an interstitial duplication of 7(q22-->q34), confirmed with fluorescent in-situ hybridization. He had post-natal growth retardation, developmental delay, frontal and parietal bossing, deep-set eyes, strabismus, bilateral optic nerve hypoplasia, and mild dilatation of the cerebral ventricles. His phenotype was not significantly different from that of the three previously reported patients with interstitial duplication of the smaller segment 7(q22-->q31).