In CLL, the lymphocytes are all genetically identical since they are derived from the same B cell lineage, expressing common B-cell markers CD19 and CD20, with abnormal expression of surface markers CD5 and CD23. These B cells resemble normal lymphocytes under the microscope, although slightly smaller, and are fragile when smeared onto a glass slide, giving rise to many broken cells, which are called "smudge" or "smear" cells and can indicate the presence of the disease. Smudge cells are due to cancer cells lacking in vimentin, a type of cytoskeleton proteins which is a structural component in a cell which maintains the cells internal shape and mechanical resilience). : 1899

Surface markers
The atypical molecular pattern on the surface of the cell includes the coexpression of cell surface markers clusters of differentiation 5 (CD5) and 23. In addition, all the CLL cells within one individual are clonal, that is, genetically identical. In practice, this is inferred by the detection of only one of the mutually exclusive antibody light chains, kappa or lambda, on the entire population of the abnormal B cells. Normal B lymphocytes consist of a stew of different antibody-producing cells, resulting in a mixture of both kappa- and lambda-expressing cells.
The author stresses the importance of genetic testing prior to deciding a prognosis for affected patients. She also proposes prenatal screening and evaluation in cases at risk for development of situs ambiguus. Recent studies have shown higher rates of heterotaxy syndrome among Hispanic infants of Mexican descent, as well as female infants of non-Hispanic black and white mothers. Additional studies must be done to clarify the mechanisms behind racial disparities in heterotaxy syndrome. Individuals of Asian descent show a higher prevalence of heterotaxy syndrome in general than members of the Western world.The National Birth Defects Prevention study (October 2014) attempted to link clinical presentations of situs ambiguus to demographics in an epidemiological study. This proved a difficult task due to the vast differences in presentation of this disorder. However, the authors are hopeful that finding a link can help inform clinical decision-making, predictive analyses, and future outcomes. See also
References
External links
radio/639 at eMedicine