Errata

No published book is free of mistakes. For a broader audience, errata are regularly published on this page as well as with the corresponding chapter within ISCN Online and as a Free Access article in the Karger Journal Cytogenetic and Genome Research.

3 Symbols, Abbreviated Terms, and General Principles

upd	Uniparental disomy (8.4, 14.2.1)

8 Numerical Chromosome Abnormalities

8.3 Autosomal Abnormalities

48,XY,+21c,+21 An acquired extra chromosome 21 in a patient with Down syndrome.

46,XY,+21c,–21 Acquired loss of one chromosome 21 in a patient with Down syndrome.

9 Structural Chromosome Rearrangements

9.1 General Principles

46,XX,inv(3)(q21q26.2) An inversion of one chromosome 3. There is no need to indicate that one chromosome 3 is missing, i.e., the karyotype should not be written 46,XX,–3,+inv(3).

9.2.1 Additional Material of Unknown Origin

46,XY,add(12)(q13)
46,XY,add(12)(pter→q13::?) Additional material of unknown origin replaces the segment 12q13qter.

9.2.3 Derivative Chromosomes

47,XX,t(9;22;6)(q34;q11.2;p21),+der(22)t(9;22;6) A three-way translocation between chromosomes 9, 22, and 6 is present along with an additional derivative chromosome 22 from this three-way translocation.

46,XY,der(9)t(9;22)(q34;q11),+22,der(22;22)(22pter→22q11::9q34→9qter::9qter→9q34::22q11→22pter) An isochromosome for the derivative chromosome 22 generated by a t(9;22), i.e., an isochromosome for the long arm of a Ph chromosome. There are also two normal copies of chromosome 22 and the derivative chromosome 9 generated by a t(9;22).

53,XX,…,+der(?)t(?;9)(?;q22),+r,+mar,dmin

9.2.5 Duplications

46,XX,dup(1)(p31p34)
46,XX,dup(1)(pter→p31::p31→p34::p31→qter) or dup(1)(pter→p34::p31→p34::p31→pter) Duplication of the segment between bands 1p34 and 1p31, in reversed orientation relative to pter and qter. Note that only the detailed form will clarify the location of the duplicated segment.

9.2.8 Homogeneously Staining Regions

46,XX,der(1)ins(1;7)(q21;p21p11.2)hsr(1;7)(q21;p11.2)
46,XX,der(1)(1pter→1q21::hsr::7p11.2→7p21::1q21→1qter) Insertion of the segment 7p21p11.2 into the long arm of chromosome 1 with breakage and reunion at band 1q21. The derivative chromosome also contains an hsr at the interface between the recipient and donor chromosomes. The hsr is located proximal to the segment inserted from chromosome 7.

46,XX,der(1)ins(1;7)(q21;p21p11.2)hsr(1;7)(q21;p21)
46,XX,der(1)(1pter→1q21::7p11.2→7p21::hsr::1q21→1qter) Insertion of the segment 7p21p11.2 into the long arm of chromosome 1 with breakage and reunion at band 1q21. The derivative chromosome also contains an hsr at the interface between the recipient and donor chromosomes. The hsr is located distal to the segment inserted from chromosome 7.

9.2.9 Insertions

The symbol ins is used for insertions. The orientation of the inserted segment is indicated by the order of the bands of the inserted segment with respect to the centromere. For clarity, the use of the detailed form is recommended.

9.2.17.1 Reciprocal Translocations

46,XX,t(5;14;9)(q13q23;q24q21;p12p23)
46,XX,t(5;14;9)(5pter→5q13::9p12→9p23::5q23→5qter;14pter→14q21::5q13→5q23::14q24→14qter;9pter→9p23::14q21→14q24::9p12→9qter) Reciprocal six-break translocation of three interstitial segments. The segment between bands 5q13 and 5q23 on chromosome 5 has replaced the segment between bands 14q21 and 14q24 on chromosome 14, the segment 14q21q24 has replaced the segment between bands 9p23 and 9p12 on chromosome 9, and the segment 9p23p12 has replaced the segment 5q13q23. The orientations of the segments in relation to the centromere are apparent from the order of the bands. The segments 9p23p12 and 14q21q24 are inverted.

11 Neoplasia

11.1.4 Stemline, Sideline and Clonal Evolution

47,XX,inv(6)(p21q25),+12[17]/50,sl,–inv(6),+7,+8,+9,+mar[11]
47,XX,inv(6)(p21q25),+12[17]/50,idem,–inv(6),+7,+8,+9,+mar[11] The inv(6) present in the stemline has not been found in the sideline with 50 chromosomes. The breakpoints in the inv(6) need not be repeated. Note that there is monosomy 6 in the sideline. If the sideline was disomic for chromosome 6 then it would be written: 50,sl,+6,–inv(6),+7,+8,+9,+mar[11] or 50,idem,+6,–inv(6),+7,+8,+9,+mar[11]

11.2 Modal Number

81<3n>,XXX,+X,+X,+X,+X,+X,+1,+1,+3,+3,+14,+14,+14,–15,+21 A tumor in a female shows 81 chromosomes but is reported relative to triploid since most chromosomes are trisomic and this is biologically significant for the disease in question, although the count is in the near-tetraploid range.

13 In situ Hybridization

13.2.1 Normal Signal Pattern

46,XX.ish 17p11.2(RAI1×2),21q21.3(D21S259/D21S341/D21S342×2) A normal female. The RAI1 locus on chromosome 17 and the Down syndrome critical region on chromosome 21 are both present in the normal copy number (two copies) as determined by ish with a locus-specific probe. All loci of the contig probe are listed.

13.2.3 Abnormal Signal Patterns with Multiple Probes

46,X,?i(Y)(p10).ish idic(Y)(q11)(DYZ3+,DYZ1–,DYZ3+) A presumed isochromosome for the short arm of Y was shown by ish to have two centromeres and no heterochromatin.

46,XX[20].ish t(12;21)(p13;q22)(ETV6+,RUNX1+;RUNX1+,ETV6+)[5] Normal female chromosomes in an oncology sample which was also tested by metaphase FISH using a dual-fusion probe and found to have an ETV6-RUNX1 gene fusion from a cryptic reciprocal translocation between chromosomes 12 and 21.

46,X,r(X).ish r(X)(p22.3q21)(KAL+,DXZ1+,XIST+,DXZ4–) A ring X was further defined by ish as containing the short arm marker KAL1, the X alpha-satellite DXZ1 and the XIST gene on the long arm. It does not include DXZ4 at Xq24.

47,XY,+der(4)t(4;11)(p34;q13),t(4;11)[20].ish der(4)(3′KMT2A+),t(4;11)(3′KMT2A+;5′KMT2A+,3′KMT2A–)[5] A male karyotype with a t(4;11) plus an extra copy of the der(4). There is a 3′KMT2A signal on both copies of the der(4). There is a 5′KMT2A signal on the der(11) component of the t(4;11).