[Absence of a gene dose effect for collagen type I and III in fibroblasts with trisomy of chromosome 7 from a spontaneously aborted human fetus].

Collagen production was studied in human embryonal fibroblasts. Synthesis of collagen in the cells with trisomy 7 was decreased 2-fold as compared with diploid cells in spite of 50% increase of the collagen genes localized on the chromosome 7. Diploid and aneuploid cells synthesized collagens of the I and III types at similar weight ratios. At the same time, an increase in synthesis of type I collagen trimer was found in culture of cells with anomalous caryotype. A decrease of collagen production in cells with anomalous caryotype appears to be one of the reasons responsible for spontaneous abortion.