A new case of congenital ficolin-3 deficiency with primary immunodeficiency

ABSTRACT

Objectives

Human Ficolin-3 (FCN3) is an oligomeric-structured lectin encoded by the FCN3 gene with a pivotal role in the lectin complement pathway. It has anti-microbial activities against bacterial and viral infections and restrains opportunistic pathogens. Mutation in the FCN3 gene is associated with variable clinical manifestations particularly immunologic (infections and autoimmunity) and neurologic complications.

Methods

In this study, we report a 5-year-old boy with a biallelic mutation in the FCN3 gene using clinical and immunological and genetic evaluations (whole exome sequencing).

Results

Our case is the first national and the eighth case worldwide with a confirmed frameshift mutation associated with Ficolin-3 deficiency. He manifested refractory seizures since early infancy, meningitis, pyelonephritis and was diagnosed with severe primary immunodeficiency.

Conclusion

Our case and literature review indicate Ficolin-3 deficiency should be considered in early-onset, premature neonate with a bacterial infection, neurological manifestation and systemic lupus erythematosus like presentations.

KEYWORDS:

• Ficolin-3 deficiency
• FCN3 gene mutation
• combined Immunodeficiency disease
• H-ficolin
• Hakata antigen

Article highlights

• Ficolin’s important roles in the innate defense against bacterial and viral infection.

• Ficolin family consists of three oligomeric-structured lectins such as Ficolin-1, Ficolin-2 and Ficolin-3

• Homozygous mutation in FCN3 is a rare condition which results in total lack of ficolin-3 protein in the serum.

• Ficolin-3 deficient cases manifest variable clinical symptoms particularly infections, autoimmunty and neourological complications

• The eighth case of confirmed homozygous FCN3 mutation that was diagnosed with severe primary immunodeficiency and had refractory seizures, pneumonia and meningitis was described.

Acknowledgments

Fateme Babaha and Hassan Abolhassani contributed equally to this article.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This paper was not funded.