Figure 2.

Proteoglycan synthesis in cells incubated in basal medium (A) or in presence of β-D-xyloside (B). Fibroblasts from Desbuquois dysplasia type 1 patients homozygous for the c.899G>A (p.R300H) and c.734delC (p.P245RfsX3) mutations in CANT1 and four controls (N1-4) were double labeled with [³⁵S]sulfate and [³H]glucosamine. (A) When cells were incubated in basal medium proteoglycan synthesis varied greatly among cultures and patient cells were within normal values. (B) A significant reduction of proteoglycan synthesis was observed in patient fibroblasts in presence of β-D-xyloside, a compound that increases glycosaminoglycan synthesis. The ³⁵S/³H ratio was within normal values (data not shown). Two independent experiments were performed and each experiment was run in triplicate; results are expressed as means ±SD. The statistical significance was calculated with the Student's t-test.