Cernunnos deficiency: a case report

Area of Science:

• Immunology
• Genetics
• Molecular Biology

Background:

• B cell-negative severe combined immunodeficiency (SCID) arises from defects in V(D)J recombination.
• Key genes in nonhomologous end joining, including DNA ligase 4 and Cernunnos, are implicated in radiosensitive SCID.
• Deficiencies in these genes can lead to microcephaly, growth retardation, and distinct facial features.

Observation:

• A patient presented with recurrent pulmonary infections, chronic lung disease, and disseminated molluscum contagiosum.
• Laboratory findings included lymphopenia, low IgG and IgA, with normal IgM levels.
• Phenotypic features included microcephaly and severe growth retardation.

Findings:

• The patient's presentation aligns with B cell-negative SCID, characterized by impaired V(D)J recombination.
• The clinical course involved significant infectious complications and developmental abnormalities.
• Despite the immunodeficiency, the patient survived infancy without autoimmune manifestations.

Implications:

• This case underscores the diverse clinical spectrum of B cell-negative SCID.
• Accurate genetic diagnosis is crucial for understanding and managing these complex primary immunodeficiencies.
• Early identification and management can improve outcomes for patients with SCID and associated genetic defects.