X-linked recessive disease.

Synopsis

 systemic anomalies

• macrosomy, gigantism, overgrowth syndrome

 carniofacial anomalies

• macrocephaly
• coarse facies
• ears anomalies: accessory tragus (preauricular pits, preauricular tags)
• eyes anomalies: downslanting palpebral fissures, hypertelorism, epicanthal folds
• nose anomalies: broad flat nasal bridge, short nose, upturned nose
• mouth anomalies: macrostomia, macroglossia, midline groove of lower lip, broad secondary alveolar ridge, submucous cleft lip, cleft palate
• dental malocclusion

 cardiovascular anomalies

• cardiac conduction defects
• ventricular septal defect
• pulmonic stenosis
• transposition of great vessels
• patent ductus arteriosus
• cardiomyopathy

 thoracic anomalies

• lung segmentation defects
• cervical ribs
• pectus excavatum
• 13 pairs of thoracic ribs
• supernumerary nipples
• diaphragmatic hernia

 abdominal anomalies

• umbilical hernia
• diastasis recti
• visceromegaly
• hepatomegaly
• hyperplastic islets of Langerhans
• polysplenia
• splenomegaly
• intestinal malrotation
• Meckel diverticulum
• cryptorchidism
• inguinal hernia

 urogenital anomalies

• nephromegaly
• renal cysts
• duplication of renal pelvis
• hypospadias

 skeletal anomalies

• advanced bone age
• vertebral segmentation defects
• fusion of C2-C3 posterior elements
• six lumbar vertebrae
• sacral defects
• coccygeal defects
• scoliosis

 limb anomalies

• flared iliac wing
• narrow sacroiliac notches in infancy
• short broad hands
• postaxial polydactyly
• syndactyly 2nd-3rd fingers
• broad thumbs
• distal phalangeal hypoplasia
• two carpal ossification centers present at birth
• short broad feet
• syndactyly 2nd-3rd toes
• broad toes
• clubfoot
• coccygeal skin tags
• fingernail hypoplasia

 cerebral anomalies

• agenesis of corpus callosum
• cerebellar vermis hypoplasia
• hydrocephalus
• hypotonia

 predisposition to tumors

• embryonal tumors
• Wilms tumor
• diffuse neonatal hemangiomatosis (#11967762#)

Etiology

 Locus SGBS1 at Xq26 (MIM.312870): mutation in the gene for glypican-3 (GPC3) (MIM.300037)
 Locus SGBS2 at Xp22 (MIM.300209)

See also

 macrosomy
 gigantism
 overgrowth syndromes