Serum transferrin in patients with retinitis pigmentosa.

The CDG syndrome is a newly detected disorder with a carbohydrate defect in glycoproteins such as transferrin. As retinitis pigmentosa is a part of this syndrome, there could also be other subtypes of retinitis pigmentosa with a similar biochemical defect. Isoforms of serum transferrin were therefore analysed in 78 patients from different families with retinitis pigmentosa and showed slightly or moderately elevated values for less glycosylated isoforms in two families. The study suggests that abnormal glycoprotein metabolism manifested by elevated values of carbohydrate-deficient isotransferrins may be present in a small proportion of families with retinitis pigmentosa. The relationship between the glycoprotein defect and retinitis pigmentosa remains to be established.