Summary
Isochromosomes are chromosomes with genetically identical arms. Chromosomes morphologically similar to isochromosomes can arise from alternative mechanisms: wholearm translocations and crossing over within inversion loops. Cases are presented which could have arisen by each of these latter two mechanisms. The first case is 46,XX,t(15;15) (qtercen-qter; pter-cen-pter) and the second 46,XY,rec(18), dup q,inv(18)(p11.32q11.2).
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References
Darlington CD (1939) Misdivision and the genetics of the centromere. J Genet 37:341–364
Darlington CD (1940) The origin of iso-chromosomes. J Genet 39:351–361
de la Chapelle A (1982) How do isochromosomes arise? Cancer Genet Cytogenet 5:173–179
Froster-Iskenius U, Coerdt W, Rehder H, Schwinger E (1984) Isochromosome 18q with karyotype 46,XX,i(18q). Cytogenetics and pathology. Clin Genet 26:549–554
Herva R, Koivisto M (1979) Trisomy 9p with i(9p) and t(9q18p). Hum Genet 50:237–240
Hsu LYF, Paciuc S, David K, Cristan S, Moloshok R, Hirschhorn K (1978) Number of C-bands of human isochromosome Xqi and relation to 45,X mosaicism. J Med Genet 15:222–226
Larson LL, Wasdahl WA, Saumur JH, Coleman ML, Jalal SM (1978) Trisomy 18 syndrome with an unusual karyotype: possible double isochromosome. J Med Genet 15:73–76
Mattei MG, Souiah N, Mattei JF (1984) Chromosome 15 anomalies and the Prader Willi syndrome: cytogenetic analysis. Hum Genet 66:313–334
Mueller HE, Buehler EM, Signer E, Egli F, Stalder GR (1972) Trisomy 18 syndrome caused by translocation or isochromosome formation. J Med Genet 9:462–467
Nikawa N, Ishikawa M (1983) Whole-arm translocation between homologous chromosomes 7 in a woman with successive spontaneous abortions. Hum Genet 63:85–86
Nusbacher J, Hirschhorn K (1969) Autosomal anomalies in man. Adv Teratol 3:1–63
Ohama K, Kusumi I, Takahara H, Kajii T (1978) Successive spontaneous abortions including one with whole-arm translocation between chromosomes 2. Hum Genet 40:221–225
Otto PG, Vianni-Morgante AM, Otto PA, Wanjntal A (1981) The Turner phenotype and the different types of human X isochromosome. Hum Genet 57:159–164
Palmer CG, Conneally PM, Christian JC (1969) Translocation of D chromosomes in two families: t(13q14q) and t(13p14p). J Med Genet 6:166–173
Sandig KR, Muecke J, Veit H (1979) Trisomy 9p resulting from de novo 9/15 translocation and a 9p isochromosome. Hum Genet 52:175–178
Schinzel A (1984) Catalogue of unbalanced chromosome aberrations. de Gruyter, New York
Schmutz SM, Pabello PD, Shokeir MHK, Jamro H (1984) Complementary products of reciprocal Robertsonian translocation of chromosome 15. Am J Hum Genet 36:111 S
Schweizer D (1980) Simultaneous fluorescent staining of R bands and specific heterochromatic regions (DA-DAPI) in human chromosomes. Cytogenet Cell Genet 27:190–193
Uchida IA, Ray M, McRae KN, Besant DF (1968) Familial occurrence of trisomy 22. Am J Hum Genet 20:107–118
Wang HC, Federoff S (1972) Banding in human chromosomes treated with trypsin. Nature New Biol 235:52–53
Ward BE, Bradley CM, Cooper JB, Robinson A (1981) Homodicentric chromosomes: a distinctive type of dicentric chromosome. J Med Genet 18:54–58
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Schmutz, S.M., Pinno, E. Morphology alone does not make an isochromosome. Hum Genet 72, 253–255 (1986). https://doi.org/10.1007/BF00291889
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DOI: https://doi.org/10.1007/BF00291889