A Novel RFXANK Mutation in a Chinese Child With MHC II Deficiency: Case Report and Literature Review

Area of Science:

• Immunology
• Genetics
• Pediatrics

Background:

• Major histocompatibility complex (MHC) II deficiency is a rare primary immunodeficiency.
• It results from deficiencies in MHC class II molecules due to transcription factor mutations.
• Mutations in the RFXANK gene are the most common cause, accounting for over 70% of cases.

Purpose of the Study:

• To report a case of MHC II deficiency caused by a novel RFXANK gene mutation in an East Asian infant.
• To review and analyze the epidemiology of MHC II deficiency and its associated gene mutations globally.
• To provide a comprehensive overview of all known gene mutations causing MHC II deficiency.

Main Methods:

• Case report of a 10-month-old boy with MHC II deficiency.
• Genetic analysis to identify mutations in transcription factor genes (CIITA, RFX5, RFXAP, RFXANK).
• Literature review of reported cases and mutation rates in different regions.

Main Results:

• A novel homozygous mutation (c.337 + 1G>C) in the RFXANK gene was identified in the patient.
• The mutation was inherited from heterozygous parents.
• The patient presented with pneumonia and diarrhea and died 3 months after diagnosis.
• This is the first reported case of MHC II deficiency from East Asia.

Conclusions:

• Novel RFXANK mutations can cause severe MHC II deficiency.
• Epidemiological data show varying mutation rates of causative genes across different regions.
• Further research is needed to understand the global genetic landscape of MHC II deficiency.