Diploid-triploid mosaicism

Diploid-triploid mosaicism is a human chromosome disorder. Individuals with diploid-triploid syndrome have some cells with three copies of each chromosome for a total of 69 chromosomes (called triploid cells) and some cells with the usual 2 copies of each chromosome for a total of 46 chromosomes (called diploid cells).[1]

Diploid-triploid mosaicism
Other namesDiploidy triploidy, 2n/3n mixoploidy, triploidy mosaicism, diploid triploid mosaic, DTM, mosaic triploid
Two children with diploid-triploid mosaicism
SpecialtyMedical genetics

Having two or more different cell types is called mosaicism. Diploid-triploid mosaicism can be associated with truncal obesity, body/facial asymmetry, weak muscle tone (hypotonia), delays in growth, mild differences in facial features, fusion or webbing between some of the fingers and/or toes (syndactyly) and irregularities in the skin pigmentation. Intellectual disabilities may be present but are highly variable from person to person ranging from mild to more severe. The chromosome disorder is usually not present in the blood; a skin biopsy, or analyzing cells in the urine is needed to detect the triploid cells.[1]

Diploid-triploid individuals may have the karyotypes 46,XX/69,XXX or 46,XX/69,XXY. Individuals with 46,XX/69,XXY karyotype typically develop as phenotypically male, but may also exhibit disorders of sexual development. Almost all diploid-triploid individuals who are phenotypically female have the karyotype 46,XX/69,XXX, but a case has been reported where a 46,XX/69,XXY individual developed as phenotypically female.[2]

Triploidy is distinct from trisomy, in which only one chromosome exists in three pairs.[3]

See also

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References

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  1. ^ a b "Diploid-triploid mosaicism". Genetic and Rare Diseases Information Center (GARD). 22 March 2010. Archived from the original on 2 April 2014. Retrieved 31 March 2014.
  2. ^ Oktem, Ozgur; Paduch, Darius A.; Xu, Kangpu; Mielnik, Anna; Oktay, Kutluk (March 2007). "Normal female phenotype and ovarian development despite the ovarian expression of the sex-determining region of Y chromosome (SRY) in a 46,XX/69,XXY diploid/triploid mosaic child conceived after in vitro fertilization-intracytoplasmic sperm injection". The Journal of Clinical Endocrinology and Metabolism. 92 (3): 1008–1014. doi:10.1210/jc.2006-1963. ISSN 0021-972X. PMID 17164312.
  3. ^ "Diploidly Triploidly" (PDF). Unique, Rare Chromosome Disorder Support Group. www.rarechromo.org. 2005. Archived from the original (PDF) on 2016-03-04. Retrieved 31 March 2014.
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