RT Journal Article SR Electronic T1 Interstitial deletion, del(4)(q33q35.1), in a mother and two children. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 652 OP 654 DO 10.1136/jmg.26.10.652 VO 26 IS 10 A1 M A Curtis A1 R A Smith A1 J Sibert A1 H E Hughes YR 1989 UL http://jmg.bmj.com/content/26/10/652.abstract AB The inheritance of autosomal deletions from affected parents has only rarely been reported. We report an unbalanced interstitial deletion, del(4)(q33q35.1), in a mother and two male offspring. The mother and older sib are mentally retarded but have only mild dysmorphic features. The younger sib, at five months, is showing signs of developmental delay. All three patients show some abnormalities in common with cases that have terminal deletions of 4q with breakpoints at 4q33, but in general exhibit less severe abnormalities. The family illustrates the importance of detailed cytogenetic analysis of children with developmental delay who do not display major dysmorphic features.