(See also Overview of Chromosome Disorders.)
In Wolf-Hirschhorn syndrome, part of chromosome 4 is missing.
Children who survive into their 20s typically have severe disabilities.
Symptoms of Wolf-Hirschhorn syndrome often include profound intellectual disability. Children may also have epilepsy, a broad or beaked nose, scalp defects, drooping upper eyelids (ptosis) and gaps or fissures (colobomas) of the iris, cleft palate, and delayed bone development. Boys may have undescended testes (cryptorchidism) and a misplaced opening of the urethra (hypospadias). Some children have an immune deficiency, which means their body is less able to fight off infections. Many affected children die during infancy.