Two sisters with onset of scleroderma in childhood initially developed similar manifestations of the disease, with flexion deformities and subcutaneous sclerosis of the distal extremities. Twelve cases involving families with more than one member affected by scleroderma were found in the literature, and the four cases that were documented in detail are summarized. The paucity of familial reports does not appear to support, as yet, an acceptable theoretic pattern of genetic transmission.
Burge KM, Perry HO, Stickler GB. "Familial" Scleroderma. Arch Dermatol. 1969;99(6):681-687. doi:10.1001/archderm.1969.01610240039006