Supernumerary Der (22)t(8;22) syndrome

Supernumerary der(22)t(8;22) syndrome

Supernumerary der(22)t(8;22) syndrome is caused by the presence of a derivative chromosome which includes a partial trisomy of part of both chromosome 8 and chromosome 22.

It can occur in children born to parents who carry the balanced translocation t(8;22)(q24.13;q11.2). Balanced translocation carriers have no missing or extra genetic material and often are only identified following the birth of a child with the unbalanced version of the translocation or following repeat miscarriages. 

Much like carriers of the more common t(11;22) translocation, carriers of the balanced constitutional translocation t(8;22)(q24.13;q11.2) are phenotypically normal but are at risk of having children with supernumerary der(22)t(8;22) syndrome. 

As with any syndrome, the supernumerary der(22)t(8;22) phenotype is variable between individuals. Common features may include ear and extremity abnormalities, differences in facial features, in addition to mild intellectual disability. 

While this condition arises in much the same way that Emanuel syndrome does, it does not feature significant birth defects or significant intellectual disability which is typically seen in Supernumerary der(22)t11;22) syndrome (Emanuel Syndrome)

OMIM Entry 613700 on Supernumerary der(22)t(8;22) syndrome

You can also join C22C’s Facebook Group to connect with other families.

Facebook group – support for carriers of balanced translocation (Not affiliated with C22C)

Select References

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Gödde-Salz, E., Oesinghaus, S., & Grote, W. (1982). Meiotic segregation in familial reciprocal translocation t(8q;22q). American Journal of Medical Genetics, 11(2), 241–247. https://doi.org/10.1002/ajmg.1320110209

Gotter, A. L., Nimmakayalu, M. A., Jalali, G. R., Hacker, A. M., Vorstman, J., Conforto Duffy, D., Medne, L., & Emanuel, B. S. (2007). A palindrome-driven complex rearrangement of 22q11.2 and 8q24.1 elucidated using novel technologies. Genome Research, 17(4), 470–481. https://doi.org/10.1101/gr.6130907

Helbig, I., Wirtenberger, M., Jauch, A., Hager, H. D., Tariverdian, G., Hemminki, K., Burwinkel, B., & Klaes, R. (2006). Trisomy 8q and partial trisomy 22 in a 43-year-old man with moderate intellectual disability, epilepsy and large cell non-Hodgkin lymphoma. American Journal of Medical Genetics. Part A, 140(15), 1658–1662. https://doi.org/10.1002/ajmg.a.31350 

Mishra, D., Kato, T., Inagaki, H., Kosho, T., Wakui, K., Kido, Y., Sakazume, S., Taniguchi-Ikeda, M., Morisada, N., Iijima, K., Fukushima, Y., Emanuel, B. S., & Kurahashi, H. (2014). Breakpoint analysis of the recurrent constitutional t(8;22)(q24.13;q11.21) translocation. Molecular Cytogenetics, 7, 55. https://doi.org/10.1186/s13039-014-0055-x 

Sheridan, M. B., Kato, T., Haldeman-Englert, C., Jalali, G. R., Milunsky, J. M., Zou, Y., Klaes, R., Gimelli, G., Gimelli, S., Gemmill, R. M., Drabkin, H. A., Hacker, A. M., Brown, J., Tomkins, D., Shaikh, T. H., Kurahashi, H., Zackai, E. H., & Emanuel, B. S. (2010). A palindrome-mediated recurrent translocation with 3:1 meiotic nondisjunction: the t(8;22)(q24.13;q11.21). American Journal of Human Genetics, 87(2), 209–218. https://doi.org/10.1016/j.ajhg.2010.07.002