Weaver syndrome

Page most recently updated 7 September 2026

This page focuses on the reported psychiatric associations, which may be the initial presenting manifestation, and on other clinical features that may assist the psychiatrist or primary care physician in identifying the underlying diagnosis, considered through the lenses of the diagnostic lenses framework.

Weaver syndrome is a rare genetic disorder. It is generally inherited in an autosomal dominant manner, with both de novo and inherited pathogenic variants occurring. The phenotype may resemble Sotos syndrome and Malan syndrome, particularly in its overgrowth, macrocephaly, and distinctive facial features, but these conditions are genetically distinct. Weaver syndrome is generally associated with milder intellectual impairment than Malan syndrome, while camptodactyly, and soft, doughy skin, may provide useful distinguishing clues. A distinctive presentation may include the combination of generalized overgrowth, macrocephaly, Sotos-like facial features, advanced bone age, and camptodactyly.

It can present with psychiatric features such as anxiety, specific phobias, autism spectrum disorder (ASD), and behavioral dysregulation. Aggression, self-injurious behavior, and attention difficulties have also been reported. Sleep disturbance may also occur. Cognitive impairment, developmental delay, and speech and language impairment are common, although intellectual function ranges from normal to severe intellectual disability. Poor coordination and difficulties with motor development may also occur.

From a morphologic lens perspective, other features include (but are not limited to):

  • Macrocephaly

  • Flat occiput

  • Micrognathia

  • Widely spaced eyes

  • Downslanted palpebral fissures

  • Protruding ears

  • Depressed nasal bridge

  • Long philtrum

  • Broad thumbs

Other characteristic features include advanced bone age, hypotonia or abnormal muscle tone, soft and doughy skin, and skeletal abnormalities, particularly camptodactyly, joint hypermobility, and scoliosis. An umbilical hernia may also occur. Neurologic manifestations may include seizures/epilepsy and structural brain abnormalities, although brain imaging abnormalities are relatively uncommon. Ophthalmologic abnormalities may include strabismus and refractive errors, while hearing impairment may also occur. Additional reported features include feeding difficulties, constipation, gastroesophageal reflux, renal and genitourinary abnormalities including cryptorchidism and hypospadias, congenital heart abnormalities, and dental abnormalities. A low-pitched or hoarse cry in infancy is characteristic. Neuroblastoma occurs at increased frequency, although the absolute risk appears to be low.

Early diagnosis is important to identify and monitor potentially significant developmental, behavioral, neurologic, musculoskeletal, cardiac, renal, auditory, ophthalmologic, gastrointestinal, and oncologic complications, recognize neuropsychiatric needs early, and institute tailored multidisciplinary surveillance and treatment.

Selected references and further reading — Morphologic lens

Jones KL, Jones MC, del Campo M. Smith's recognizable patterns of human malformation. 8th ed. Philadelphia: Elsevier; 2021.

Reardon W. The bedside dysmorphologist: a guide to identifying and assessing congenital malformations. 2nd ed. Oxford: Oxford University Press; 2016.

Allanson JE, Biesecker LG, Carey JC, Hennekam RCM. Elements of morphology: introduction. Am J Med Genet A. 2009;149A(1):2-5. doi:10.1002/ajmg.a.32601.

Hennekam RCM, Biesecker LG, Allanson JE, Hall JG, Opitz JM, Temple IK, Carey JC; Elements of Morphology Consortium. Elements of morphology: general terms for congenital anomalies. Am J Med Genet A. 2013;161A(11):2726-2733. doi:10.1002/ajmg.a.36249.