Title:Hereditary Heterozygous C2 Deficiency: Variable Clinical and Serological Manifestations Among Three Sisters
Volume: 13
Issue: 2
Author(s): Ji Wei Yang, Eric Rich, Claire Saint-Cyr and Josiane Bourré-Tessier*
Affiliation:
- Centre Hospitalier de l’Université de Montréal, Hôpital Notre-Dame, 1560 Sherbrooke Street East, Montréal, QC H2L 4M1,Canada
Keywords:
Systemic lupus erythematosus, complement deficiency, autoimmune disorders, antiphospholipid syndrome.
Abstract: The causal link between inherited complement deficiencies and systemic lupus erythematosus
(SLE) has been well established, although it remains a rare cause of the disease. We present the
case of three biological sisters with hereditary heterozygous C2 deficiency, but who differ widely in
their clinical and serological manifestations. Patient 1 is 25 years old and was diagnosed with SLE at
the age of 12. Further testing revealed positive ANA and anti-dsDNA, antiphospholipid syndrome
(APS) and decreased C2, C3 and C4 levels. Patients 2 and 3 are 21-year-old dizygotic twins. Both
have positive ANA and antiphospholipid (APL) antibodies, and decreased C2 and C4 levels. We
present a case of familial heterozygous C2 deficiency with different disease phenotypes. The presence
of positive APL antibodies in all 3 patients is significant, as this association has been rarely
described. The variable clinical and serological manifestations among our patients further reflect the
complex and multifactorial nature of SLE.
