Summary
Extra chromosome material on the short arm of chromosome no. 6 (46,XY,6p+) was found in two mentally retarded adult half-brothers with mildly dysmorphic features. The phenotypically normal mother had a balanced translocation between the long arm of chromosome no. 1 and the short arm of chromosome no. 6: 46,XX,t(1;6)(q32;p25). Thus the two affected brothers were trisomic for the long arm segment of chromosome no. 1, distal to q32. These patients, with mildly dysmorphic features and mental retardation, represent the first cases of partial trisomy 1q surviving to adulthood.
The clinical and cytogenetic data obtained from eight individuals with partial trisomies for different long arm segments of chromosome no. 1 suggest that partial trisomy of the distal two-thirds of the long arm is characterized by severe malformations, growth retardation, and early death. Conversely, partial trisomy for the distal one-third of the long arm is associated with milder malformations and longer survival time as well as growth and mental retardation.
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References
Ganner, E., Evans, H. J.: The relationship between patterns of DNA replication and of quinacrine fluorescence in the human chromosome complement. Chromosoma 35, 326–341 (1971)
Garrett, J. H., Finley, S. C., Finley, W. H.: Fetal loss and familial chromosome 1 translocations. Clin. Genet. 8, 341–348 (1975)
Holmberg, M., Jonasson, J.: Preferential location of x-ray induced chromosome breakage in the R-bands of human chromosomes. Hereditas 74, 57–68 (1973)
Neu, R. L., Gardner, L. I.: A partial trisomy of chromosome 1 in a family with a t(1q-;4q+) translocation. Clin. Genet. 4, 474–479 (1973)
Norwood, T. H., Hoehn, H.: Trisomy of the long arm of human chromosome 1. Humangenetik 25, 79–82 (1974)
Sanchez, O., Yunis, J. J.: New chromosome techniques and their medical applications. In: New Chromosomal Syndromes (J. J. Yunis, Ed.), p. 41. New York: Academic Press 1977
Steffensen, D. M., Chu, E. H. Y., Speert, D. P., Wall, P. M., Meilinger, K., Kelch, R. P.: Partial trisomy of the long arm of human chromosome 1 as demonstrated by in situ hybridization with 5S ribosomal RNA. Hum. Genet. 36, 25–33 (1977)
Van den Berghe, H., Eygen, M. van, Fryns, J. P., Tanghe, W., Verresen, H.: Partial trisomy 1, karyotype 46,XY,12-,t(1q,12p)+. Humangenetik 18, 225–230 (1973)
Yunis, E., Egel, H., Zuniga, R., Ramirez, E., Caballero, O. M. T. de, Leibovici, M.: ‘De novo’ trisomy 1q32→1qter and monosomy 3p25→3pter. Hum. Genet. 36, 113–116 (1977)
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Taysi, K., Sekhon, G.S. Partial trisomy of chromosome no. 1 in two adult brothers due to maternal translocation (1q-;6p+). Hum Genet 44, 277–285 (1978). https://doi.org/10.1007/BF00394292
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DOI: https://doi.org/10.1007/BF00394292