Summary
Cytogenetic analysis of a 6-year-old girl with moderate mental retardation revealed 46 chromosomes with a tandem translocation (21;21) resulting in a partial trisomy 21. Only the terminal band 21q22 was not in triplicate. G-, Q-, R-, and C-banding techniques and silver nitrate staining of the nucleolus organizer regions (NORs) were used to identify this chromosome fully.
The phenotype of the patient was not typical for Down's syndrome, providing additional evidence that trisomy of band 21q22 is pathogenetic for the phenotype of Down's syndrome. This is also a new example in human pathology of a stable ‘dicentric’ chromosome in which one of the centromeric constrictions appears to be nonfunctional.
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References
Aula, P., Leisti, J., von Koskull, H.: Partial trisomy 21. Clin. Genet. 4, 241–251 (1973)
Bartsch-Sandhoff, M., Schade, H.: Zwei subterminale Heterochromatinregionen bei einer seltenen Form einer 21/21-Translokation. Humangenetik 18, 329–336 (1973)
Chen, H., Tyrkus, M., Woolley, Jr., P. V.: Partial trisomy 21 due to maternal t(12;21) translocation: Further evidence that the Down phenotype is related to trisomy of the distal segment of chromosome 21. Proc. of the Vth Intern. Congr. Hum. Genet., Mexico, 1976. Excerpta Medica, int. congr. series 397, 116 (1976)
de la Chapelle, A., Stenstrand, K.: Dicentric human X chromosomes Hereditas 76, 259–268 (1974)
Denton, T. E., Howell, W. M., Barrett, J. V.: Human nucleolar organizer chromosomes: Satellite associations. Chromosoma (Berl.) 55, 81–84 (1976)
Distèche, C., Hagemeijer, A., Frederic, J., Progneaux, D.: An abnormal large human chromosome identified as an end-to-end fusion of two X's by combined results of the new banding techniques and microdensitometry. Clin. Genet. 3, 388–395 (1972).
Fraisse, J., Laurent, C., Collard, N., Biemont, M. C., Dutrillaux, B.: Un deuxième exemple de fusion télomerique de deux chromsomes X. Ann. Génét. 18, 243–245 (1975)
Hagemeijer, A., Hoovers, J., Hasper-Voogt, I., Von Ruhe-Zurcher, T., Bootsma, D.: Latereplicating ring X-chromosomes identified by R-banding after BrdU pulse. Three new examples of mosaicism 45, XO/46, Xr(X). Hum. Genet. 34, 45–52 (1976)
Jernigan, D., Curl, N., Keeler, C.: Milledgeville mongoloid: a rare karyotype of Down's syndrome. J. Hered. 65, 254–257 (1974)
Kadotani, T., Ohama, K., Takahara, H., Nagai, I., Shimizu, B., Makino, S.: A case of Down's syndrome associated with G/G translocation. Proc. Japan Acad. 46, 858–862 (1970)
Laurent, C., Biemont, M. C., Dutrillaux, B.: Sur quatre nouveaux cas de translocation du chromosome X chez l'homme. Humangenetik 26, 35–46 (1975)
Lee, L. G., Jackson, J. F.: Diagnosis of Down's syndrome: clinical vs. Laboratory. Clin. Pediat. (Phila.) 11, 353–356 (1972)
Lejeune, J., Berger, R., Vidal, O. R., Rethoré, M. O.: Un cas de translocation G∼G en tandem. Ann. Génét. 8, 60–62 (1965)
Niebuhr, E.: Down's syndrome. The possibility of a pathogenetic segment on chromosome No. 21. Humangenetik 21, 99–101 (1974)
Poissonnier, M., Saint-Paul, B., Dutrillaux, B., Chassaigne, M., Gruyer, P., de Blignières-Strouk, G.: Trisomie 21 partielle (21q21→21q22.2). Ann. Génét. 19, 69–73 (1976)
Ruthner, U., Golob, E.: Fusion of the short arms of one X-chromosome in a patient with gonadal dysgenesis. Humangenetik 24, 159–160 (1974)
Sinet, P. M., Couturier, J., Dutrillaux, B., Poissonnier, M., Raoul, O., Rethoré, M. O., Allard, D., Lejeune, J., Jérome, H.: Trisomie 21 et superoxyde dismutase-1 (IPO-A). Tentative de localisation sur la sous bande 21q22.1. Exp. Cell Res. 97, 47–55 (1976)
Therman, E., Sarto, G. E., Pätau, K.: Apparently isodicentric but functionally monocentric X chromosome in man. Amer. J. hum. Genet. 26, 83–92 (1974)
Therman, E., Pätau, K.: Abnormal X chromosomes in man: Origin, behavior and effects. Humangenetik 25, 1–16 (1974)
Verma, R. S., Lubs, H. A.: A simple R banding technic. Amer. J. hum. Genet. 27, 110–117 (1975)
Vogel, W.: Identification of G-group chromosomes involved in a G/G tandem-translocation by the Giemsa-banding technique. Humangenetik 14, 255–256 (1972)
Wahrman, J., Goitein, R., Richler, C., Goldman, B., Akstein, E., Chaki, R.: The mongoloid phenotype in man is due to trisomy of the distal pale G-band of chromosome 21. In: Chromosomes today, P. L. Pearson, K. R. Lewis, eds., Vol. 5, pp. 241–248. Israël Universities Press 1976
Warkany, J., Soukup, S. W.: A chromosomal abnormality in a girl with some features of Down's syndrome (mongolism). J. Pediat. 62, 890–894 (1963)
White, M. J. D.: Some general problems of chromosomal evolution and speciation in animals. Survey Biol. Progr. (N.Y.) 3, 109–147 (1957)
Williams, J. D., Summitt, R. L., Martens, P. R., Kimbrell, R. A.: Familial Down syndrome due to t(10;21) translocation: Evidence that the Down phenotype is related to trisomy of a specific segment of chromosome 21. Amer. J. hum. Genet. 27, 478–485 (1975)
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Hagemeijer, A., Smit, E.M.E. Partial trisomy 21. Hum Genet 38, 15–23 (1977). https://doi.org/10.1007/BF00295803
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DOI: https://doi.org/10.1007/BF00295803