C1q deficiency with severe skin manifestations: A case report from Pakistan

Background: C1q deficiency is a rare autosomal recessive disorder associated with increased susceptibility to infections and autoimmune diseases, notably systemic lupus erythematosus (SLE). Due to its rarity and varied presentation, there are no established guidelines for management. Due to highly variable clinical symptomatology, standard treatment approaches are lacking. Case presentation: We report the case of an 11-month-old Pakistani girl presenting with a desquamating rash and recurrent infections. Initial management with multiple antibiotics and antifungals was ineffective. Upon admission to our facility, clinical and laboratory evaluations indicated severe immunodeficiency. Whole exome sequencing (WES) identified a novel homozygous likely pathogenic variant in the C1qA (c..474C > G, p.Tyr158*), leading to C1q deficiency. Treatment included corticosteroids, antibiotics, and fresh frozen plasma (FFP) transfusions, resulting in clinical improvement. Discussion: C1q deficiency, though rare, presents with diverse clinical manifestations, primarily cutaneous and infectious. Early genetic diagnosis is essential for appropriate management. This case underscores the potential role of FFP in treating C1q deficiency, though more research is needed on its efficacy and safety. Conclusion: This case emphasizes the importance of recognizing C1q deficiency in patients suspected of an underlying immunodeficiency syndrome. Clinical response to FFP infusions suggests that these patients if identified early can have control of symptoms. Early molecular diagnosis through genetic testing and tailored therapeutic approaches are crucial for improving outcomes in these patients. Further research into targeted therapies and the broader implications of C1q in health and disease is essential.