t(2;22)(p23;q11) CLTCL1/ALK

2001-08-01   Jean-Loup Huret 

1.Genetics, Dept Medical Information, University of Poitiers, CHU Poitiers Hospital, F-86021 Poitiers, France

Clinics and Pathology


  • Translocations involving 2p23 are found in more than half cases of anaplasic large cell lymphoma (ALCL), a high grade non Hodgkin lymphoma (NHL). They involve ALK, and are therefore called ALK+ ALCL.
  • The most frequent ALK+ ALCL being the the t(2;5)(p23;q35) with NPM1 -ALK fusion protein, which localises both in the cytoplasm and in the nucleus.
  • The t(2;22)(p23;Q11.2) is very rare, and, like other t(2;Var) involving various partners and ALK, the fusion protein has a cytoplasmic localization; they are therefore called "cytoplasm only" ALK+ ALCL. However, in case of a t(2;22) the localization is restricted to granules (vesicles) in the cytoplasm.
  • Phenotype stem cell origin

    CD30+; ALK+


    found in 1 case ( a 3 yr old girl in complete remission 1yr after end of treatment), perhaps 2 (a 52 yr old man).

    Genes Involved and Proteins

    Gene name
    ALK (anaplastic lymphoma receptor tyrosine kinase)
    Protein description
    1620 amino acids; 177 kDa; glycoprotein (200 kDa mature protein) ; membrane associated tyrosine kinase receptor
    Gene name
    CLTCL1 (clathrin heavy polypeptide-like 1)
    Protein description
    1640 amino acids, 187 kDa; component of the coat of vesicles originated from the plasma membrane or the golgi

    Result of the Chromosomal Anomaly


    5 CLTCL1 - 3 ALK2197 amino acids, 248-250 kDa; 1634 (nearly all the CLTCL1 protein) N-term amino acids from CLTCL1, fused to the 562 C-term amino acids from ALK (i.e. the entire cytoplasmic portion of ALK with the tyrosine kinase domain).

    Expression localisation

    cytoplasmic localization restricted to granules


    constitutive autophosphorylation


    Pubmed IDLast YearTitleAuthors
    109949992000Pathobiology of NPM-ALK and variant fusion genes in anaplastic large cell lymphoma and other lymphomas.Drexler HG et al
    87331291996Characterization of a second human clathrin heavy chain polypeptide gene (CLH-22) from chromosome 22q11.Kedra D et al
    113803912001Alk+ CD30+ lymphomas: a distinct molecular genetic subtype of non-Hodgkin's lymphoma.Morris SW et al
    110900482000CD30(+) anaplastic large cell lymphoma: a review of its histopathologic, genetic, and clinical features.Stein H et al
    108077892000Further demonstration of the diversity of chromosomal changes involving 2p23 in ALK-positive lymphoma: 2 cases expressing ALK kinase fused to CLTCL (clathrin chain polypeptide-like).Touriol C et al


    Fusion gene

    CLTCL1/ALK CLTCL1 (22q11.21) ALK (2p23.2) M t(2;22)(p23;q11)


    Jean-Loup Huret

    t(2;22)(p23;q11) CLTCL1/ALK

    Atlas Genet Cytogenet Oncol Haematol. 2001-08-01

    Online version: http://atlasgeneticsoncology.org/haematological/1220/t(2;22)(p23;q11)