karyotype

karyotype A standard arrangement of the chromosome complement prepared for chromosome analysis. A normal female karyotype would include each of the 22 pairs of autosomes (nonsex chromosomes), arranged in numeric order, together with the two X chromosomes.

Kartagener syndrome

Kartagener syndrome A genetic syndrome that is characterized by sinusitis, bronchiectasis (widening and inflammation of the bronchi), dextrocardia (heart on the right side of the chest), and infertility. Kartagener syndrome is inherited in an autosomal recessive manner. Kartagener syndrome is usually due to mutation in the gene called DNAI1 on chromosome 9. However, linkage studies…

Kaposi sarcoma

Kaposi sarcoma A relatively rare type of skin malignancy that tends to affect elderly people and those with an abnormal immune system, as in AIDS. Kaposi sarcoma is caused by human herpesvirus 8 (HHV-8), which may be transmitted via kissing. Kaposi sarcoma is a highly vascular (angioblastic) tumor of the skin, characterized by soft purplish…

kala-azar

kala-azar A chronic and potentially fatal parasitic disease of the viscera (the internal organs, particularly the liver, spleen, bone marrow, and lymph nodes) due to infection by the parasite Leishmania donovani. Leishmania donovani is transmitted by sandfly bites in parts of Asia (primarily India), Africa (primarily Sudan), and South America (primarily Brazil). Kala-azar can cause…

K

K The symbol for potassium, the major positive ion (cation) found inside cells. A proper level of potassium is essential for normal cell function. An abnormal increase in potassium (hyperkalemia) or an abnormal decrease in potassium (hypokalemia) can profoundly affect the nervous system and the heart and, if extreme, can be fatal.