The presence of
isochromosome 12p (made up of two p arms) causes the disorder.
UPD associated with an
isochromosome was reported in cases with i(1p) plus i(1q), i(2p) plus i(2q), i(4p) plus i(4q), i(7p) plus i(7q), psudic (8)(p23.3), i(9p) plus i(9q), i(13q), i(14q), i(15q), i(21q), and i(22q) (35, 36).
Luleci, "Turner Syndrome with
Isochromosome Xq and Familial Reciprocal Translocation t(4;16)(p15.2; p13.1)," Balkan Journal of Medical Genetics, vol.
The most common structural cytogenetic abnormality in seminoma is presence of
isochromosome 12p.
Monosomy X (45,X) is the most common overall karyotype, encountered in approximately 45% of diagnosed cases, whereas the most common X chromosome structural defect is the
isochromosome 46,X,i(X)(q10) that comprises approximately 15-18% of total cases of TS [3].
Berman, "An
isochromosome confers drug resistance in vivo by amplification of two genes, ERG11 and TAC1," Molecular Microbiology, vol.
(3) Extragonadal GCTs share the gain of
isochromosome 12p with gonadal GCTs.
However strong evidence that this supernumerary is an
isochromosome was given by some additional mitotic and meiotic studies, which also indicated that its heterochromatic nature is related with the amplification and dispersion of highly repetitive sequences (Mestriner et al., 2000; Moreira-Filho et al., 2004; Vicari et al., 2011).
Cytogenetic analysis revealed complex abnormal findings with
isochromosome of 5p, rearrangement of chromosome 6, and loss of chromosomes 18 and 20 in all cells examined.
has cells with 45,X and cells with 46,XX), karyotypes with an
isochromosome of X--for example i(Xq) or i(Xp)--or karyotypes with an entire or part of an Y chromosome.
An
isochromosome 3q+ (i3)(q10) has also been described in a varying proportion of the B cell population [3, 18].