Alternative titles; symbols
ORPHA: 169147;
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
Gene/Locus |
Gene/Locus MIM number |
|---|---|---|---|---|---|---|
| 12p13.31 | C1s deficiency | 613783 | 3 | C1S | 120580 |
A number sign (#) is used with this entry because of evidence that selective complement component C1s deficiency (C1SD) is caused by homozygous mutation in the C1S gene (120580) on chromosome 12p13.
Complement component C1s deficiency (C1SD) is an autosomal recessive disorder characterized by the presence of autoimmune diseases including a systemic lupus erythematosus-like disorder, Hashimoto thyroiditis, autoimmune hepatitis, and chronic glomerulonephritis (Inoue et al., 1998, Dragon-Durey et al., 2001).
Inoue et al. (1998) reported a patient with a systemic lupus erythematosus-like syndrome and chronic glomerulonephritis in whom no C1s protein was detectable by immunoblot. By Northern blot and RT-PCR analysis, C1s mRNA was of appropriate size, but only 10% of the level detected in HCS2/8, a human chondrosarcoma cell line. Levels of beta-actin and C1r (216950) mRNA were similar to levels detected in HCS2/8.
In a 27-month-old girl with multiple autoimmune diseases, Dragon-Durey et al. (2001) determined that an absence of plasma C1S accounted for a lack of classic complement (CH50) pathway activity. At age 5, the child was alive and well while receiving immunosuppressive drugs daily and penicillin.
Inoue et al. (1998) reported a patient with selective C1s deficiency resulting from a homozygous mutation in the C1S gene (120580.0001).
In a 27-month-old girl with multiple autoimmune diseases, Dragon-Durey et al. (2001) detected selective C1S deficiency resulting from a nonsense mutation in exon 12 of the C1S gene (120580.0002). Restriction enzyme analysis showed that the propositus was homozygous for the mutation, while a paternal grandmother, maternal grandfather, and aunts on both sides of the family were heterozygous. The mutation was not detected in systemic lupus erythematosus (152700) patients or unrelated Caucasian controls, including some from the same geographic region.
Dragon-Durey, M.-A., Quartier, P., Fremeaux-Bacchi, V., Blouin, J., de Barace, C., Prieur, A.-M., Weiss, L., Fridman, W.-H. Molecular basis of a selective C1s deficiency associated with early onset multiple autoimmune diseases. J. Immun. 166: 7612-7616, 2001. [PubMed: 11390518] [Full Text: https://doi.org/10.4049/jimmunol.166.12.7612]
Inoue, N., Saito, T., Masuda, R., Suzuki, Y., Ohtomi, M., Sakiyama, H. Selective complement C1s deficiency caused by homozygous four-base deletion in the C1s gene. Hum. Genet. 103: 415-418, 1998. [PubMed: 9856483] [Full Text: https://doi.org/10.1007/s004390050843]