1.5Mb deletion of chromosome 4p16.3 associated with postnatal growth delay, psychomotor impairment, epilepsy, impulsive behavior and asynchronous skeletal development.

[wolf-hirschhorn syndrome]

Several Wolf-Hirschhorn syndrome patients have been studied , mouse models for a few candidate genes have been constructed and two WHS critical regions have been postulated , but the molecular basis of the syndrome remains poorly understood . Single gene contributions to phenotypes of microdeletion syndromes have often been based on the study of patients carrying small , atypical deletions . We report a 5 -year -old girl harboring an atypical 1 .5 Mb del 4 p 16 .3 and review seven previously published patients carrying a similar deletion . They show a variable clinical presentation and the only consistent feature is post-natal growth delay . However , four of eight patients carry a ring (4 ), and ring chromosomes in general are associated with growth deficiency . The Greek helmet profile is absent , although a trend towards common dysmorphic features exists . Variable expressivity and incomplete penetrance might play a role in WHS , resulting in difficult clinical diagnosis and challenge in understanding of the genotype /phenotype correlation .