NLE appears to occur in about 1 in 20,000 live births and can affect all ethnic groups. Females are affected by NLE preferentially 2:1 for cutaneous lupus, but males and females are equally affected with congenital heart block (CHB); 70% to 80% of babies with CHB had NLE.
One percent of NLE patients develop hepatic disease. Thrombocytopenia or neutropenia is observed in about 10% of cases. Both usually resolve within weeks of birth.