Down syndrome laboratory findings: Difference between revisions
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==Overview== | ==Overview== | ||
Down syndrome is confirmed through [[Cytogenetic analysis|Cytogenetic studies]] which confirm trisomy 21. In addition [[complete blood count]] with differentials is performed to rule out [[leukemia]], [[Thyroid-stimulating hormone|TSH]] and [[T4]] are performed at birth, 6 months, 1 year and then annually to rule out [[hypothyroidism]]. Low level of [[Immunoglobulin G|IgG]] subclass 4 are correlated with bacterial infections. The mosaic trisomy 21 includes [[lymphocyte]] preparations, [[Fluorescence in situ hybridization|FISH]],[[buccal mucosa]] cellular preparations and scoring frequency of trisomic cells. | |||
==Laboratory Findings== | ==Laboratory Findings== | ||
*The following lab tests are done for the patients of Down syndrome to rule out conditions associated with down syndrome:<ref>Ringman JM, Rao N, Lu PH, Cederbaum S. Mosaicism for trisomy 21 in a patient with young-onset dementia. A case report and brief literature review. Arch Neurol. 2008. 65:412-415.</ref><ref name="PapavassiliouYork2009">{{cite journal|last1=Papavassiliou|first1=Paulie|last2=York|first2=Timothy P.|last3=Gursoy|first3=Nurcan|last4=Hill|first4=Gloria|last5=Nicely|first5=Lauren Vanner|last6=Sundaram|first6=Usha|last7=McClain|first7=Allison|last8=Aggen|first8=Steven H.|last9=Eaves|first9=Lindon|last10=Riley|first10=Brien|last11=Jackson-Cook|first11=Colleen|title=The phenotype of persons having mosaicism for trisomy 21/Down syndrome reflects the percentage of trisomic cells present in different tissues|journal=American Journal of Medical Genetics Part A|volume=149A|issue=4|year=2009|pages=573–583|issn=15524825|doi=10.1002/ajmg.a.32729}}</ref> | *The following lab tests are done for the patients of Down syndrome to rule out conditions associated with down syndrome:<ref>Ringman JM, Rao N, Lu PH, Cederbaum S. Mosaicism for trisomy 21 in a patient with young-onset dementia. A case report and brief literature review. Arch Neurol. 2008. 65:412-415.</ref><ref name="PapavassiliouYork2009">{{cite journal|last1=Papavassiliou|first1=Paulie|last2=York|first2=Timothy P.|last3=Gursoy|first3=Nurcan|last4=Hill|first4=Gloria|last5=Nicely|first5=Lauren Vanner|last6=Sundaram|first6=Usha|last7=McClain|first7=Allison|last8=Aggen|first8=Steven H.|last9=Eaves|first9=Lindon|last10=Riley|first10=Brien|last11=Jackson-Cook|first11=Colleen|title=The phenotype of persons having mosaicism for trisomy 21/Down syndrome reflects the percentage of trisomic cells present in different tissues|journal=American Journal of Medical Genetics Part A|volume=149A|issue=4|year=2009|pages=573–583|issn=15524825|doi=10.1002/ajmg.a.32729}}</ref> | ||
**CBC with differentials to rule out Leukemia | **[[CBC]] with differentials to rule out [[Leukemia]] | ||
**To rule out hypothyroid, the following tests are performed at birth, 6 months, 1 year and then annually: | **To rule out [[Hypothyroidism|hypothyroid]], the following tests are performed at birth, 6 months, 1 year and then annually: | ||
***TSH | ***[[TSH]] | ||
***T4 | ***[[T4]] | ||
**Cytogenetic studies | **[[Cytogenetic analysis|Cytogenetic studies]] | ||
***Cytogenetic studies are performed for the confirmation of down syndrome | ***[[Cytogenetic analysis|Cytogenetic studies]] are performed for the confirmation of down syndrome | ||
***Karyotyping must be performed to determine the risk of recurrence | ***[[Karyotype|Karyotyping]] must be performed to determine the risk of recurrence | ||
**Measurement of Immunoglobulin G | **Measurement of [[Immunoglobulin G]] | ||
***Subsequent low level of IgG subclass 4 are correlated with bacterial infections | ***Subsequent low level of IgG subclass 4 are correlated with bacterial infections | ||
**The Mosaic trisomy 21 that includes: | **The [[Mosaicism|Mosaic]] trisomy 21 that includes: | ||
***Lymphocyte preparations | ***[[Lymphocyte]] preparations | ||
***FISH | ***[[Fluorescence in situ hybridization|FISH]] | ||
***Buccal mucosa cellular preparations | ***[[Buccal mucosa]] cellular preparations | ||
***Scoring frequency of trisomic cells | ***Scoring frequency of trisomic cells | ||
**Interphase fluorescence in situ hybridization (FISH) | **[[Fluorescence in situ hybridization|Interphase fluorescence in situ hybridization]] (FISH) | ||
***Interphase fluorescence in situ hybridization is used for early and rapid detection of trisomy 21 | ***Interphase fluorescence in situ hybridization is used for early and rapid detection of trisomy 21 | ||
***The FISH test is beneficial in the diagnosis of Down syndrome in prenatal and neonatal period | ***The FISH test is beneficial in the diagnosis of Down syndrome in prenatal and neonatal period | ||
Revision as of 23:01, 20 March 2018
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Dildar Hussain, MBBS [2]
Overview
Down syndrome is confirmed through Cytogenetic studies which confirm trisomy 21. In addition complete blood count with differentials is performed to rule out leukemia, TSH and T4 are performed at birth, 6 months, 1 year and then annually to rule out hypothyroidism. Low level of IgG subclass 4 are correlated with bacterial infections. The mosaic trisomy 21 includes lymphocyte preparations, FISH,buccal mucosa cellular preparations and scoring frequency of trisomic cells.
Laboratory Findings
- The following lab tests are done for the patients of Down syndrome to rule out conditions associated with down syndrome:[1][2]
- CBC with differentials to rule out Leukemia
- To rule out hypothyroid, the following tests are performed at birth, 6 months, 1 year and then annually:
- Cytogenetic studies
- Cytogenetic studies are performed for the confirmation of down syndrome
- Karyotyping must be performed to determine the risk of recurrence
- Measurement of Immunoglobulin G
- Subsequent low level of IgG subclass 4 are correlated with bacterial infections
- The Mosaic trisomy 21 that includes:
- Lymphocyte preparations
- FISH
- Buccal mucosa cellular preparations
- Scoring frequency of trisomic cells
- Interphase fluorescence in situ hybridization (FISH)
- Interphase fluorescence in situ hybridization is used for early and rapid detection of trisomy 21
- The FISH test is beneficial in the diagnosis of Down syndrome in prenatal and neonatal period
- The FISH test needs to be confirmed by a complete karyotype analysis as it does not provide information about the trisomy 21 to weather if it is secondary to a translocation
References
- ↑ Ringman JM, Rao N, Lu PH, Cederbaum S. Mosaicism for trisomy 21 in a patient with young-onset dementia. A case report and brief literature review. Arch Neurol. 2008. 65:412-415.
- ↑ Papavassiliou, Paulie; York, Timothy P.; Gursoy, Nurcan; Hill, Gloria; Nicely, Lauren Vanner; Sundaram, Usha; McClain, Allison; Aggen, Steven H.; Eaves, Lindon; Riley, Brien; Jackson-Cook, Colleen (2009). "The phenotype of persons having mosaicism for trisomy 21/Down syndrome reflects the percentage of trisomic cells present in different tissues". American Journal of Medical Genetics Part A. 149A (4): 573–583. doi:10.1002/ajmg.a.32729. ISSN 1552-4825.