Meyahealth
HomeGeneticsGeneRAB3GAP2 gene
Back to Gene
RAB3GAP2 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

RAB3GAP2 gene

The RAB3GAP2 gene provides instructions for a protein that regulates GTPases, which are essential for vesicle trafficking, hormone release, and cellular organization.

Normal Function

The RAB3GAP2 gene provides instructions for a protein that helps regulate GTPases, which act as molecular switches that control various cellular functions. The RAB3GAP2 protein interacts with the RAB3GAP1 protein to form the RAB3GAP complex.

  • Regulating RAB18: The complex turns on the GTPase RAB18, which is involved in vesicle trafficking, the storage and release of fats (lipids), and autophagy (clearing unneeded materials from cells). RAB18 is also important for the organization of the endoplasmic reticulum.
  • Regulating RAB3: The complex is thought to inactivate the GTPase RAB3, which plays a role in the release of hormones and neurotransmitters.

Health Conditions Related to Genetic Changes

RAB18 deficiency

At least 10 RAB3GAP2 gene mutations have been found to cause RAB18 deficiency, resulting in conditions affecting the eyes, brain, and reproductive system.

  • Warburg micro syndrome: Occurs when mutations prevent the production of any RAB3GAP2 protein or completely eliminate its function. This is at the severe end of the spectrum.
  • Martsolf syndrome: Caused by mutations that reduce the amount of functional RAB3GAP2 protein. This is at the mild end of the spectrum.

The reduction or loss of this protein impairs the RAB3GAP complex, leading to a deficiency in RAB18 activity. It is currently unclear why the loss of RAB18 function leads to the specific eye and brain abnormalities associated with these syndromes.

Other Names for This Gene

  • DKFZP434D245
  • KIAA0839
  • p150
  • RAB3 GTPase activating protein subunit 2 (non-catalytic)
  • rab3 GTPase-activating protein 150 kDa subunit
  • rab3 GTPase-activating protein non-catalytic subunit
  • rab3-GAP p150
  • rab3-GAP regulatory subunit
  • RAB3-GAP150
  • RAB3GAP150
  • RGAP-iso
  • SPG69
  • WARBM2

Frequently Asked Questions

For neurological symptoms, caregivers should watch for significant delays in reaching developmental milestones (e.g., sitting, walking, speaking), seizures, muscle weakness or spasticity, and difficulties with feeding. Regarding vision, signs to monitor include poor eye tracking, lack of response to visual stimuli, nystagmus (involuntary eye movements), cloudiness in the eyes (cataracts), or unusually small eyes. Regular neurological and ophthalmological evaluations are crucial for early intervention and management.
Warburg micro syndrome is the more severe form, typically resulting from mutations that completely eliminate the RAB3GAP2 protein's function. It presents with profound developmental delays, severe intellectual disability, microcephaly (small head size), and significant eye abnormalities like microphthalmia (small eyes) and cataracts. Martsolf syndrome is generally milder, caused by mutations that only reduce the protein's function. Individuals with Martsolf syndrome also experience developmental delays and intellectual disability, but often less severe, along with eye issues such as cataracts and optic atrophy, and sometimes hypogonadism.
Diagnosis is usually confirmed through genetic testing, specifically sequencing of the RAB3GAP2 gene, which can identify the specific mutations. This is often done after clinical suspicion based on the characteristic symptoms. For family planning, genetic counseling is highly recommended. Since these conditions are typically inherited in an autosomal recessive pattern, parents who have one affected child are carriers and have a 25% chance of having another affected child with each pregnancy. Carrier testing for parents and prenatal diagnosis options can be discussed with a genetic counselor.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

Meyahealth

Ⓒ 2026. All rights reserved by MEYA

About UsTerms & PolicyFAQ