A new syndrome of proximal deletion of the long arm of chromosome 1: 1q21–23→1q25

Abstract
We present two unrelated children with the de novo interstitial deletion of the proximal segment of the long arm of chromosome 1 (1q21–23→1q25). Comparison of the phenotypic characteristics of these two patients with those of two previously described patients with similar deletion confirms the existence of the proximal 1q deletion syndrome. The characteristics of this newly recognized deletion syndrome include pre‐ and postnatal growth retardation; severe psychomotor retardation; microbrachycephaly; sparse, fine scalp hair and eyebrows; cleft lip and palate; hernias; genitalia defects; small hands and feet; and clinodactyly of the fifth fingers.