Hereditary deficiency of C2 in association with linear scleroderma 'en coup de sabre'

A 32-year-old man suffering from linear frontoparietal scleroderma was found to have low (less than 10% normal) serum classical pathway activity although C1q, C3, C4, C5, and total alternative pathway activity was normal. Addition of purified C2 led to complete restoration of the total hemolytic activity of the classical pathway. The C2 hemolytic assays showed that the patient was not totally deficient in C2. He had about 30% of the normal C2 level. Studies on his available nucleus family members in the Netherlands also showed that the deficiency was inherited; one of the patient's brothers and one of his daughters had half of the normal C2 levels. The C2 deficiency could not be corrected by a three-week regimen of danazol. To the best of our knowledge, this is the first documented case concerning an association of linear frontoparietal scleroderma with C2 deficiency.