Simpson–Golabi–Behmel syndrome (SGBS) is a rare inherited congenital disorder that can cause craniofacial, skeletal, vascular, cardiac, and renal abnormalities.

Females that possess one copy of the mutation are considered to be carriers of the syndrome but may still express varying degrees of the phenotype, suffering mild to severe malady.

OGS is characterized by a two to three standard deviation increase in weight, height, or head circumference above the average for sex and age.

[3] Limb patterning and skeletal development may also go awry when GPC3 mutations inhibit regulations of responses to bone morphogenetic proteins, another type of growth factor.

[4] It has been suggested that SGBS type II may be caused by duplication of the GPC4 gene, which helps to regulate cell division and growth.

When large for gestational age fetuses (LGA) are identified, there are two common causes: maternal diabetes or incorrect dates.

[citation needed] Once the infant is born, possibility of hypoglycemia must be assessed along with cardiac, genitalia, liver, and adrenal evaluations.

[citation needed] Due to the likelihood of patients developing tumors, full body CT scans are a recommended diagnostic tool.

As there have been cases in which the genetic mutation is accompanied by further genetic presence of the bard 1 gene and presence of triple negative cancers, those with such dual expressions cannot rely upon standardized biopy for determination of cancer, but should resort to further diagnostic tools (i.e. those such as pet scans which measure chemical and decay rate factors for diagnosis).