National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Intrinsic factor deficiency



Other Names:
IFD; Pernicious anemia, congenital, due to defect of intrinsic factor; Congenital pernicious anemia due to defect of intrinsic factor; IFD; Pernicious anemia, congenital, due to defect of intrinsic factor; Congenital pernicious anemia due to defect of intrinsic factor; Intrinsic factor, congenital deficiency of; Congenital intrinsic factor deficiency See More
Categories:

Intrinsic factor deficiency is a rare condition that is characterized by pernicious anemia and neurological abnormalities. Most affected people develop signs and symptoms of the condition before age 5 years which may include failure to thrive and symptoms related to anemia (i.e. fatigue, pale skin, etc). Without early diagnosis and treatment, nervous system damage may occur which can be associated with confusion; depression; and numbness or tingling in the hands and/or feet.[1] Intrinsic factor deficiency is caused by changes (mutations) in the GIF gene and is inherited in an autosomal recessive manner.[2][3] Treatment generally consists of vitamin B12 injections.[1]
Last updated: 1/19/2016

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
Percent of people who have these symptoms is not available through HPO
Abnormality of metabolism/homeostasis
Laboratory abnormality
Metabolism abnormality
[ more ]
0001939
Abnormality of the immune system
Immunological abnormality
0002715
Absence of intrinsic factor 0005219
Autosomal recessive inheritance 0000007
Increased mean corpuscular volume 0005518
Juvenile onset
Signs and symptoms begin before 15 years of age
0003621
Malabsorption
Intestinal malabsorption
0002024
Malabsorption of Vitamin B12 0200118
Megaloblastic anemia 0001889
Megaloblastic erythroid hyperplasia 0200143
Paresthesia
Pins and needles feeling
Tingling
[ more ]
0003401
Sensory impairment 0003474
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Last updated: 7/1/2020

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnosis includes Imerslund-Gräsbeck syndrome, transcobalamin II deficiency, cblF defect, and acquired pernicious anemia (see these terms), which is caused by autoimmunity or Helicobacter infection.
Visit the Orphanet disease page for more information.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this 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.

Where to Start

  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Intrinsic factor deficiency. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.


  1. Paul Schick, MD. Pernicious Anemia. Medscape Reference. August 2015; http://emedicine.medscape.com/article/204930-overview.
  2. Congenital intrinsic factor deficiency. Orphanet. September 2011; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=332.
  3. INTRINSIC FACTOR DEFICIENCY. OMIM. May 2014; http://www.omim.org/entry/261000.