Plasma fibronectin deficiency in eight members of one family.

The proband, a 31-year-old female, had keloids at the sites of surgery and burns. Her plasma fibronectin level measured by Laurell's method was only 10 mg/dl (mean +/- SD in 101 healthy controls 32.2 +/- 5.6 mg/dl) but the electrophoretic mobility was normal. Low levels of plasma fibronectin (range 11-17 mg/dl) were found in the proband's mother, two uncles, two brothers, one daughter, and one nephew. Levels in her father and other family members examined were normal (range 32-51 mg/dl). The proband has been quite healthy, an haematological and haemostatic tests showed no abnormality except reduced phagocytosis by neutrophils. Other family members with low plasma fibronectin levels had no abnormalities on examination and no keloids.