From NCBI curation
EZH2-related overgrowth includes EZH2-related Weaver syndrome at one end of the spectrum and tall stature at the other. Although most individuals diagnosed with a heterozygous EZH2 mutation have been identified because of a clinical suspicion of Weaver syndrome, a minority have been identified through molecular genetic testing of family members of probands or individuals with overgrowth who did not have a clinical diagnosis of Weaver syndrome. Thus, the extent of the phenotypic spectrum associated with heterozygous EZH2 mutations is not yet known. Weaver syndrome is characterized by tall stature, variable intellect (ranging from normal intellect to severe intellectual disability), characteristic facial appearance, and a range of associated clinical features including advanced bone age, poor coordination, soft doughy skin, camptodactyly of the fingers or toes, umbilical hernia, abnormal tone, and hoarse low cry in infancy. Neuronal migration disorders have also been reported in a few individuals with EZH2-related overgrowth. Malignancies (including neuroblastoma and hematologic malignancies) may occur with increased frequently; current data are insufficient to draw conclusions.

From OMIM
Weaver syndrome (WVS) comprises pre- and postnatal overgrowth, accelerated osseous maturation, characteristic craniofacial appearance, and developmental delay. Most cases are sporadic, although autosomal dominant inheritance has been reported. Although there is phenotypic overlap between Weaver syndrome and Sotos syndrome (117550), distinguishing features of Weaver syndrome include broad forehead and face, ocular hypertelorism, prominent wide philtrum, micrognathia, deep horizontal chin groove, and deep-set nails. In addition, carpal bone development is advanced over the rest of the hand in Weaver syndrome, whereas in Sotos syndrome carpal bone development is at or behind that of the rest of the hand (summary by Basel-Vanagaite, 2010). Sotos syndrome (117550), which shows considerable phenotypic overlap with Weaver syndrome, is caused by mutation in the NSD1 gene (601573) on chromosome 5q35. Other 'Weaver-like' syndromes include Cohen-Gibson syndrome (COGIS; 617561), caused by heterozygous mutation in the EED gene (605984) on chromosome 11q14; and Imagawa-Matsumoto syndrome (IMMAS; 618786), caused by heterozygous mutation in the SUZ12 gene (606245) on chromosome 17q11. The 'Weaver-like' syndrome reported by Stoll et al. (1985) in a mother and son may be a separate entity.  http://www.omim.org/entry/277590

From MedlinePlus Genetics
Weaver syndrome is a condition that involves tall stature with or without a large head size (macrocephaly), a variable degree of intellectual disability (usually mild), and characteristic facial features. These features can include a broad forehead; widely spaced eyes (hypertelorism); large, low-set ears; a dimpled chin, and a small lower jaw (micrognathia).

People with Weaver syndrome can also have joint deformities called contractures that restrict the movement of affected joints. The contractures may particularly affect the fingers and toes, resulting in permanently bent digits (camptodactyly). Other features of this disorder can include abnormal curvature of the spine (kyphoscoliosis); muscle tone that is either reduced (hypotonia) or increased (hypertonia); loose, saggy skin; and a soft-outpouching around the belly-button (umbilical hernia). Some affected individuals have abnormalities in the folds (gyri) of the brain, which can be seen by medical imaging; the relationship between these brain abnormalities and the intellectual disability associated with Weaver syndrome is unclear.

Researchers suggest that people with Weaver syndrome may have an increased risk of developing cancer, in particular a slightly increased risk of developing a tumor called neuroblastoma in early childhood, but the small number of affected individuals makes it difficult to determine the exact risk.  https://medlineplus.gov/genetics/condition/weaver-syndrome