Familial interstitial deletion of chromosome 4 (p15.2p16.1).

Interstitial deletion of the proximal short arm of chromosome 4, extending from p14 to p16.1 region, results in a distinct clinical syndrome. This proximal 4p deletion syndrome is characterized by variable degrees of mental retardation, unusual facies and minor dysmorphic features. Majority of the patients also show a tall, ectomorphic habitus and normal to excessive linear growth with age. While there have been several cases of such interstitial del(4p) cases reported, familial transmission of this condition has not been documented in the literature. This is the first report of a familial transmission of proximal del(4p) from a mother to her daughter, with both patients showing similar features. This report of the familial transmission of del(4p) has wider implications in genetic counseling.