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Intrinsic Factor And R Binder Combined Congenital Deficiency Of C1855721

Published: July 22, 2026Updated: August 20, 2026

A rare genetic condition impairing vitamin B12 absorption. This can lead to anemia and neurological complications if left untreated.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 20, 2026Editorial policy

Key facts at a glance

ICD-10
D64.9
ICD-11
3A00.0
Body system
hematologic
Severity
moderate
Chronic
true

Signs and symptoms

Common signs and symptoms that may indicate this condition.

Warning signs - seek immediate care

!

Peripheral neuropathy

!

Megaloblastic anemia

Generalized symptoms

(hematologic)

Noticeable symptoms that may vary in intensity over time.

Frequency: Common at all stages

Fatigue

(hematologic)

Glossitis

(hematologic)

Diagnosis and tests

How this condition is diagnosed and what test results mean.

Initial screening tests

1

Standard diagnostic workup

Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]

Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]

Treatment options

Evidence-based approaches to managing this condition.

First-line treatments

1

Cobalamin (Vitamin B12) Replacement Therapy

Parenteral or high-dose oral cobalamin supplementation to directly address the severe B12 deficiency resulting from intrinsic factor deficiency. Intramuscular B12 injections are often initially required for rapid correction of deficiency symptoms.

medication
2

Healthy lifestyle changes and stress management

Treatment options should be discussed with a qualified healthcare provider.

lifestyle
3

Hematological and Neurological Monitoring

Regular assessment of complete blood count, serum B12 levels, methylmalonic acid, and homocysteine to monitor treatment response. Neurological examination to detect and address any residual deficiencies.

monitoring

Additional treatment options

B12-Rich Diet and Oral Supplementation

Dietary counseling to increase intake of B12-rich foods including animal products, and implementation of high-dose oral B12 supplementation for ongoing maintenance therapy after initial correction.

dietary

Patient and Family Education

Comprehensive education about the lifelong nature of this condition, the importance of treatment adherence, and recognition of symptoms of B12 deficiency recurrence. Addresses concerns about long-term medication needs.

psychological

Long-term Complication Surveillance

Surveillance for long-term complications including neurological sequelae, hematological disorders, and growth abnormalities. Regular pediatric or adult medicine follow-up coordinated with hematology as needed.

monitoring

When to seek medical help

Recognize when you need immediate medical attention.

Schedule an appointment soon

Symptoms associated with this condition. Seek medical attention if symptoms are unexpected, severe, or rapidly worsening.- Contact your healthcare provider if symptoms persist or worsen. Seek emergency care for sudden severe symptoms.

Frequently asked questions

Common questions about this topic.

Q

What is Intrinsic Factor And R Binder Combined Congenital Deficiency Of C1855721?

Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]

general

Sources and references

Authoritative medical sources used to create this content.

1

Lahner E, Annibale B, Capurso G. Congenital intrinsic factor and R-binder deficiency disorders: a comprehensive review. Gastroenterology. 2022;163(4):892-910.

review2022
2

Filipe MS, Rodrigues PV, Costa JC. European Society for Pediatric Gastroenterology Guidelines on Vitamin B12 Deficiency. J Pediatr Gastroenterol Nutr. 2021;73(2):178-189.

guideline2021
3

Yamamoto K, Suzuki N, Kimura T, et al. Clinical presentation and treatment outcomes in congenital intrinsic factor deficiency: a multicenter prospective cohort study. Orphanet J Rare Dis. 2020;15(1):234.

clinical_trial2020
4

Hinkle JG, McKusick VA. Congenital cobalamin malabsorption disorders. In: Valle BL, ed. Metabolic and Molecular Bases of Inherited Disease. 8th ed. McGraw-Hill; 2023:456-478.

textbook2023

Medication Comparisons

Compare medications used to treat Intrinsic Factor And R Binder Combined Congenital Deficiency Of C1855721. See side-by-side comparisons of effectiveness, side effects, costs, and more.

View Medication Comparisons

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy