Discordant disease expression of neonatal lupus erythematosus in twins.

Neonatal lupus erythematosus is an autoimmune disease resulting from the trans-placental passage of maternal anti-SSA/Ro, anti-SSB/La, and less frequently anti-RNP antibodies to the foetus. At the time of diagnosis 50% of mothers are asymptomatic. Neonatal manifestations of this multisystem disease may include congenital heart block, cutaneous lesions and haematological abnormalities. We present the case of congenital neonatal lupus erythematosus in non-identical twins, showing variability in clinical manifestation of this disease,despite receiving the same level of antibodies from the mother. This case adds to the growing body of evidence about the role of genetics and other feto-maternal contributing factors in addition to the presence of auto antibodies. It raises interesting questions about discordant disease expression in offspring's of the same mother.