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Increased HbA2 hemoglobin

MedGen UID:
893100
Concept ID:
C4073172
Finding
Synonym: Increased hemoglobin A2
 
HPO: HP:0045048

Definition

An elevated concentration in the blood of hemoglobin A2 (HbA2), which is a normal variant of hemoglobin A that consists of two alpha and two delta chains and is normally present at low levels in adults but may be increased in beta thalassemia. [from HPO]

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVIncreased HbA2 hemoglobin

Conditions with this feature

Dominant beta-thalassemia
MedGen UID:
347036
Concept ID:
C1858990
Disease or Syndrome
Dominantly inherited inclusion body beta-thalassemia is characterized by the presence of inclusion bodies in red blood cell precursors, moderately severe anemia, jaundice, and splenomegaly (summary by Ropero et al., 2005).
Trichothiodystrophy 6, nonphotosensitive
MedGen UID:
934752
Concept ID:
C4310785
Disease or Syndrome
About half of all people with trichothiodystrophy have a photosensitive form of the disorder, which causes them to be extremely sensitive to ultraviolet (UV) rays from sunlight. They develop a severe sunburn after spending just a few minutes in the sun. However, for reasons that are unclear, they do not develop other sun-related problems such as excessive freckling of the skin or an increased risk of skin cancer. Many people with trichothiodystrophy report that they do not sweat.\n\nIntellectual disability and delayed development are common in people with trichothiodystrophy, although most affected individuals are highly social with an outgoing and engaging personality. Some people with trichothiodystrophy have brain abnormalities that can be seen with imaging tests. A common neurological feature of this disorder is impaired myelin production (dysmyelination). Myelin is a fatty substance that insulates nerve cells and promotes the rapid transmission of nerve impulses.\n\nMothers of children with trichothiodystrophy may experience problems during pregnancy including pregnancy-induced high blood pressure (preeclampsia) and a related condition called HELLP syndrome that can damage the liver. Babies with trichothiodystrophy are at increased risk of premature birth, low birth weight, and slow growth. Most children with trichothiodystrophy have short stature compared to others their age. \n\nTrichothiodystrophy is also associated with recurrent infections, particularly respiratory infections, which can be life-threatening. People with trichothiodystrophy may have abnormal red blood cells, including red blood cells that are smaller than normal. They may also have elevated levels of a type of hemoglobin called A2, which is a protein found in red blood cells. Other features of trichothiodystrophy can include dry, scaly skin (ichthyosis); abnormalities of the fingernails and toenails; clouding of the lens in both eyes from birth (congenital cataracts); poor coordination; and skeletal abnormalities including degeneration of both hips at an early age.\n\nThe signs and symptoms of trichothiodystrophy vary widely. Mild cases may involve only the hair. More severe cases also cause delayed development, significant intellectual disability, and recurrent infections; severely affected individuals may survive only into infancy or early childhood.\n\nIn people with trichothiodystrophy, tests show that the hair is lacking sulfur-containing proteins that normally gives hair its strength. A cross section of a cut hair shows alternating light and dark banding that has been described as a "tiger tail."\n\nTrichothiodystrophy, commonly called TTD, is a rare inherited condition that affects many parts of the body. The hallmark of this condition is hair that is sparse and easily broken. 

Professional guidelines

PubMed

Langlois S, Ford JC, Chitayat D; CCMG PRENATAL DIAGNOSIS COMMITTEE; SOGC GENETICS COMMITTEE
J Obstet Gynaecol Can 2008 Oct;30(10):950-959. doi: 10.1016/S1701-2163(16)32975-9. PMID: 19038079

Recent clinical studies

Etiology

Lin Q, Xie Y, Zhong X, Sun X, Wang D
BMC Med Genomics 2022 Aug 15;15(1):179. doi: 10.1186/s12920-022-01333-6. PMID: 35971149Free PMC Article
Gašperšič J, Kristan A, Kunej T, Zupan IP, Debeljak N
Blood Transfus 2021 Nov;19(6):518-532. Epub 2020 Dec 16 doi: 10.2450/2020.0197-20. PMID: 33370224Free PMC Article
Andrea Mosca, Renata Paleari, Barbara Wild; IFCC Working Group on Standardization of HbA₂
Clin Chem Lab Med 2013 May;51(5):937-41. doi: 10.1515/cclm-2012-0575. PMID: 23027585
Harteveld CL, Higgs DR
Orphanet J Rare Dis 2010 May 28;5:13. doi: 10.1186/1750-1172-5-13. PMID: 20507641Free PMC Article
Giambona A, Passarello C, Renda D, Maggio A
Clin Biochem 2009 Dec;42(18):1786-96. Epub 2009 Jul 8 doi: 10.1016/j.clinbiochem.2009.06.026. PMID: 19591816

Diagnosis

Sahoo S, Sahu N, Das P, Senapati U
Indian J Pathol Microbiol 2023 Apr-Jun;66(2):327-331. doi: 10.4103/ijpm.ijpm_233_21. PMID: 37077076
Gašperšič J, Kristan A, Kunej T, Zupan IP, Debeljak N
Blood Transfus 2021 Nov;19(6):518-532. Epub 2020 Dec 16 doi: 10.2450/2020.0197-20. PMID: 33370224Free PMC Article
Aliyeva G, Asadov C, Mammadova T, Gafarova S, Abdulalimov E
Clin Chem Lab Med 2018 Dec 19;57(2):165-174. doi: 10.1515/cclm-2018-0647. PMID: 30138112
Bento C
Int J Lab Hematol 2018 May;40 Suppl 1:62-67. doi: 10.1111/ijlh.12828. PMID: 29741264
Harteveld CL, Higgs DR
Orphanet J Rare Dis 2010 May 28;5:13. doi: 10.1186/1750-1172-5-13. PMID: 20507641Free PMC Article

Therapy

Csader S, Ismaiah MJ, Kuningas T, Heinäniemi M, Suhonen J, Männistö V, Pentikäinen H, Savonen K, Tauriainen MM, Galano JM, Lee JC, Rintamäki R, Karisola P, El-Nezami H, Schwab U
Int J Mol Sci 2023 May 9;24(10) doi: 10.3390/ijms24108509. PMID: 37239856Free PMC Article
Zhu J, Li H, Aerbajinai W, Kumkhaek C, Pirooznia M, Saxena A, Dagur P, Chin K, Rodgers GP
Blood 2022 Nov 24;140(21):2276-2289. doi: 10.1182/blood.2021014877. PMID: 36399071Free PMC Article
Asadov Ch, Alimirzoyeva Z, Hasanova M, Mammadova T, Shirinova A
Georgian Med News 2016 Jun;(255):86-92. PMID: 27441542
Bhagat P, Kaur Sachdeva R, Sharma P, Updesh Singh Sachdeva M, Chhabra S, Sharma A, Das R
Infect Dis (Lond) 2016 Feb;48(2):122-6. Epub 2015 Oct 2 doi: 10.3109/23744235.2015.1089592. PMID: 26431373
Ou Z, Li Q, Liu W, Sun X
Tohoku J Exp Med 2011 Mar;223(3):223-6. doi: 10.1620/tjem.223.223. PMID: 21403433

Prognosis

Roubinian NH, Reese SE, Qiao H, Plimier C, Fang F, Page GP, Cable RG, Custer B, Gladwin MT, Goel R, Harris B, Hendrickson JE, Kanias T, Kleinman S, Mast AE, Sloan SR, Spencer BR, Spitalnik SL, Busch MP, Hod EA; National Heart Lung and Blood Institute (NHLBI) Recipient Epidemiology and Donor Evaluation Study IV Pediatrics (REDS-IV-P)
JCI Insight 2022 Jan 11;7(1) doi: 10.1172/jci.insight.152598. PMID: 34793330Free PMC Article
Bento C
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Vincent O, Oluwaseyi B, James B, Saidat L
Ethiop J Health Sci 2016 Nov;26(6):517-522. doi: 10.4314/ejhs.v26i6.3. PMID: 28450766Free PMC Article
Ou Z, Li Q, Liu W, Sun X
Tohoku J Exp Med 2011 Mar;223(3):223-6. doi: 10.1620/tjem.223.223. PMID: 21403433
Odenheimer DJ, Whitten CF, Rucknagel DL, Sarnaik SA, Sing CF
Am J Hum Genet 1983 Nov;35(6):1224-40. PMID: 6196966Free PMC Article

Clinical prediction guides

Kambe J, Miyata S, Li C, Yamamoto Y, Nagaoka K
Behav Brain Res 2023 Jul 9;449:114476. Epub 2023 May 5 doi: 10.1016/j.bbr.2023.114476. PMID: 37148916
Roubinian NH, Reese SE, Qiao H, Plimier C, Fang F, Page GP, Cable RG, Custer B, Gladwin MT, Goel R, Harris B, Hendrickson JE, Kanias T, Kleinman S, Mast AE, Sloan SR, Spencer BR, Spitalnik SL, Busch MP, Hod EA; National Heart Lung and Blood Institute (NHLBI) Recipient Epidemiology and Donor Evaluation Study IV Pediatrics (REDS-IV-P)
JCI Insight 2022 Jan 11;7(1) doi: 10.1172/jci.insight.152598. PMID: 34793330Free PMC Article
Korporaal A, Gillemans N, Heshusius S, Cantú I, van den Akker E, van Dijk TB, von Lindern M, Philipsen S
Haematologica 2021 Feb 1;106(2):464-473. doi: 10.3324/haematol.2019.239830. PMID: 32467144Free PMC Article
Bento C
Int J Lab Hematol 2018 May;40 Suppl 1:62-67. doi: 10.1111/ijlh.12828. PMID: 29741264
Harteveld CL, Higgs DR
Orphanet J Rare Dis 2010 May 28;5:13. doi: 10.1186/1750-1172-5-13. PMID: 20507641Free PMC Article

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