The purpose of this study is to unravel the proportion of monogenic lupus in children onset Systemic lupus erythematosus (SLE), and to find out the diagnostic strategy for early detection of monogenic lupus.

Childhood Systemic Lupus Erythematosus (SLE) is a common autoimmune disease in children, with a high incidence in Asia. Compared with adult SLE, childhood SLE is more likely to involve multiple systems, the treatment is more difficult, and mortality is relatively high. With the improvement of diagnosis and treatment of SLE, the prognosis of children with SLE continues to improve, but there are still a small number of patients who are ineffective to existing treatments. The pathogenesis of SLE is complicated, and more and more evidences confirm that genetic factors are involved in the pathogenesis of SLE. In recent years, the concept of "Monogenic Lupus" has been proposed internationally, and more than 30 single gene variants have been found to be related to the onset of SLE. Such patients are clinically in line with typical SLE or lupus-like syndrome, with common characteristics of a very young age of onset (mostly in infants and young children), and/or a family history of rheumatic immune diseases. It is a huge difficulty to early identify these patients at present, and it has not been generally accepted in the field of rheumatology in China.

In this research, about 200 patients with childhood onset SLE that meet the criteria for inclusion and exclusion were tested for gene analysis, and clinical data were collected and entered into the SLE cohort database. The incidence of monogenic lupus in childhood onset SLE will be unraveled. Based on clinical key words, such as early onset, male, family history of rheumatic diseases, blood system involvement, kidney involvement, the incidence of monogenic lupus in these single or multiple keyword combination will be calculated and compared to obtain an early, cost-effective diagnosis strategy for monogenic lupus.

Inclusion Criteria:

Subjects who meet the following criteria will be allowed to participate in the study:

1. onset age: birth to 18 years;
2. meet the diagnostic criteria of SLE according to ACR(1997), or SLICC(2012), or EULAR/ACR (2019);
3. obtain parental consent.

Exclusion Criteria:

1. Lack of clinical data;
2. Unable to finish the follow-up.

Participants in this group were derived from patients diagnosed with SLE at an age of less than 18 years old, and these patients were hospitalized in our center.