The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.
| Signs and Symptoms | Approximate number of patients (when available) |
| 1-3 toe syndactyly | 90% |
| Macrocephaly | 90% |
| Postaxial hand polydactyly | 90% |
| Preaxial foot polydactyly | 90% |
| Broad hallux | 89% |
| Wide nasal bridge | 79% |
| High forehead | 70% |
| Frontal bossing | 58% |
| Abnormality of the nose | 50% |
| Accelerated skeletal maturation | 50% |
| Finger syndactyly | 50% |
| Hypertelorism | 50% |
| Telecanthus | 50% |
| Toe syndactyly | 50% |
| 3-4 finger syndactyly | 33% |
| Broad hallux phalanx | 33% |
| Broad thumb | 33% |
| Abnormal heart morphology | 7.5% |
| Abnormality of muscle fibers | 7.5% |
| Agenesis of corpus callosum | 7.5% |
| Aplasia/Hypoplasia of the corpus callosum | 7.5% |
| Camptodactyly of toe | 7.5% |
| Cognitive impairment | 7.5% |
| Congenital diaphragmatic hernia | 7.5% |
| Craniosynostosis | 7.5% |
| Cryptorchidism | 7.5% |
| Delayed cranial suture closure | 7.5% |
| Hirsutism | 7.5% |
| Hydrocephalus | 7.5% |
| Hyperglycemia | 7.5% |
| Hypospadias | 7.5% |
| Inguinal hernia | 7.5% |
| Intellectual disability, mild | 7.5% |
| Joint contracture of the hand | 7.5% |
| Postaxial foot polydactyly | 7.5% |
| Preaxial hand polydactyly | 7.5% |
| Seizures | 7.5% |
| Umbilical hernia | 7.5% |
| Metopic synostosis | 5% |
| Autosomal dominant inheritance | - |
| Dolichocephaly | - |
| Trigonocephaly | - |
| Variable expressivity | - |
Different genetic changes involving the GLI3 gene can cause GCPS. In some cases, the condition results from a chromosome abnormality—such as a large deletion or rearrangement of genetic material—in the region of chromosome 7 that contains the GLI3 gene. In other cases, a mutation in the GLI3 gene itself is responsible for the disorder. Each of these genetic changes prevents one copy of the gene in each cell from producing any functional protein. It remains unclear how a reduced amount of this protein disrupts early development and causes the characteristic features of GCPS.[1]
Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.
Nonprofit support and advocacy groups bring together patients, families, medical professionals, and researchers. These groups often raise awareness, provide support, and develop patient-centered information. Many are the driving force behind research for better treatments and possible cures. They can direct people to research, resources, and services. Many groups also have experts who serve as medical advisors. Visit their website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.
Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.
These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.
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I am researching the link between Greig cephalopolysyndactyly syndrome, hydrocephalus, and seizures. I am curious about the reason for the hydrocephalus: is it a blockage issue or a slow draining issue? See answer
