Molecular Genetics of Holt–Oram Syndrome


The Holt–Oram syndrome (HOS) is an autosomal‐dominant hand–heart syndrome characterised by malformations of the upper limbs, mainly involving the preaxial (radial) ray, and variable cardiac defects. Mutations in TBX5, a transcription factor that regulates a wide variety of developmental processes, underlie HOS. Thus far, more than a hundred TBX5 mutations have been identified in patients with HOS. However, only the application of stringent diagnostic criteria will lead to a high sensitivity and specificity in TBX5 mutation screening. Various pathogenic mechanisms that lead to HOS have been uncovered, ranging from loss‐of‐function to gain‐of‐function. Nonetheless, in a significant minority of HOS patients, who do fulfil the strict diagnostic criteria, no TBX5 mutation is identified. This suggests that mutations in regulatory parts of TBX5 could cause disease, or mutations in genes other than TBX5 could underlie HOS. Application of exome sequencing or even whole‐genome sequencing should be pursued in those cases.

Key Concepts:

  • Holt–Oram syndrome is caused by TBX5 mutations.

  • The majority of TBX5 mutations lead to loss‐of‐function.

  • Application of stringent diagnostic criteria increases the yield of TBX5 mutation screening in HOS patients.

  • In a minority of HOS patients, who fulfil the stringent diagnostic criteria, no TBX5 mutation is identified.

  • TBX5 is involved in the specification of the mesoderm and development of the heart, vasculature and limbs.

Keywords: Holt–Oram syndrome; TBX5; transcription factor; DNA‐binding; limb malformation; cardiac defects

Figure 1.

Overview of the TBX5 protein and its various domains: T‐box, nuclear localisation signals (NLS), nuclear export signal (NES) and activation domain (AD). Mutations that have been molecularly tested and are present in the T‐box have been highlighted.



Akrami SM, Winter RM, Brook JD and Armour JA (2001) Detection of a large TBX5 deletion in a family with Holt‐Oram syndrome. Journal of Medical Genetics 38(12): e44. doi: 10.1136/jmg.38.12.e44.

Albalat R, Baquero M and Minguillon C (2010) Identification and characterisation of the developmental expression pattern of tbx5b, a novel tbx5 gene in zebrafish. Gene Expression Patterns 10(1): 24–30.

Alby C, Bessieres B, Bieth E et al. (2013) Contiguous gene deletion of TBX5 and TBX3 leads to a varible phenotype with combined features of Holt‐Oram and ulnar‐mammary syndromes. American Journal of Medical Genetics Part A 161A(7): 1797–1802.

Atik T, Dervisoglu H, Onay H, Ozkinay F and Cogulu O (2014) A new mutation in the TBX5 gene in Holt‐Oram syndrome: two cases in the same family and prenatal diagnosis. Journal of Tropical Pediatrics. PMID: 24408148.

Baban A, Pitto L, Pulignani S et al. (2014) Holt‐Oram syndrome with intermediate atrioventricular canal defect, and aortic coarctation: functional characterization of a de novo TBX5 mutation. American Journal of Medical Genetics Part A. doi: 10.1002/ajmg.a.36459.

Bamshad M, Lin RC, Law DJ et al. (1997) Mutations in human TBX3 alter limb, apocrine and genital development in ulnar‐mammary syndrome. Nature Genetics 16(3): 311–315.

Barnett P, van den Boogaard M and Christoffels V (2012) Localized and temporal gene regulation in heart development. Current Topics in Developmental Biology 100: 171–201.

Barron MR, Belaguli NS, Zhang SX et al. (2005) Serum response factor, an enriched cardiac mesoderm obligatory factor, is a downstream gene target for Tbx genes. Journal of Biological Chemistry 280(12): 11816–11828.

Basson CT, Bachinsky DR, Lin RC et al. (1997) Mutations in human TBX5 [corrected] cause limb and cardiac malformation in Holt‐Oram syndrome. Nature Genetics 15(1): 30–35.

Basson CT, Cowley GS, Solomon SD et al. (1994) The clinical and genetic spectrum of the Holt‐Oram syndrome (heart‐hand syndrome). New England Journal of Medicine 330(13): 885–891.

Basson CT, Huang T, Lin RC et al. (1999) Different TBX5 interactions in heart and limb defined by Holt‐Oram syndrome mutations. Proceedings of the National Academy of Sciences of the USA 96(6): 2919–2924.

Bohm J, Heinritz W, Craig A et al. (2008) Functional analysis of the novel TBX5 c.1333delC mutation resulting in an extended TBX5 protein. BMC Medical Genetics 9: 88.

van den Boogaard M, Smemo S, Burnicka‐Turek I et al. (2014) A common genetic variant within SCN10A modulates cardiac SCN5A expression. Journal of Clinical Investigation 124(4): 1844–1852.

van den Boogaard M, Wong LY, Tessadori F et al. (2012) Genetic variation in T‐box binding element functionally affects SCN5A/SCN10A enhancer. Journal of Clinical Investigation 122(7): 2519–2530.

Boogerd CJ, Dooijes D, Ilgun A et al. (2010) Functional analysis of novel TBX5 T‐box mutations associated with Holt‐Oram syndrome. Cardiovascular Research 88(1): 130–139.

Boogerd CJ, Moorman AF and Barnett P (2009) Protein interactions at the heart of cardiac chamber formation. Annals of Anatomy 191(6): 505–517.

Boogerd CJ, Wong LY, van den Boogaard M et al. (2011) Sox4 mediates Tbx3 transcriptional regulation of the gap junction protein Cx43. Cellular and Molecular Life Sciences 68(23): 3949–3961.

Boogerd KJ, Wong LY, Christoffels VM et al. (2008) Msx1 and Msx2 are functional interacting partners of T‐box factors in the regulation of Connexin43. Cardiovascular Research 78(3): 485–493.

Borozdin W, Bravo Ferrer Acosta AM, Bamshad MJ et al. (2006) Expanding the spectrum of TBX5 mutations in Holt‐Oram syndrome: detection of two intragenic deletions by quantitative real time PCR, and report of eight novel point mutations. Human Mutation 27(9): 975–976.

Brassington AM, Sung SS, Toydemir RM et al. (2003) Expressivity of Holt‐Oram syndrome is not predicted by TBX5 genotype. American Journal of Human Genetics 73(1): 74–85.

Brown DD, Martz SN, Binder O et al. (2005) Tbx5 and Tbx20 act synergistically to control vertebrate heart morphogenesis. Development 132(3): 553–563.

Bruneau BG, Logan M, Davis N et al. (1999) Chamber‐specific cardiac expression of Tbx5 and heart defects in Holt‐Oram syndrome. Developmental Biology 211(1): 100–108.

Bruneau BG, Nemer G, Schmitt JP et al. (2001) A murine model of Holt‐Oram syndrome defines roles of the T‐box transcription factor Tbx5 in cardiogenesis and disease. Cell 106(6): 709–721.

Chambers JC, Zhao J, Terracciano CM et al. (2010) Genetic variation in SCN10A influences cardiac conduction. Nature Genetics 42(2): 149–152.

Christoffels VM, Habets PE, Franco D et al. (2000) Chamber formation and morphogenesis in the developing mammalian heart. Developmental Biology 223(2): 266–278.

Cross SJ, Ching YH, Li QY et al. (2000) The mutation spectrum in Holt‐Oram syndrome. Journal of Medical Genetics 37(10): 785–787.

Csaba E, Marta V and Endre C (1991) Holt‐Oram syndroma. Orvosi Hetilap 132: 73–78.

Debeer P, Race V, Gewillig M et al. (2007) Novel TBX5 mutations in patients with Holt‐Oram syndrome. Clinical Orthopaedics and Related Research 462: 20–26.

Demay F, Bilican B, Rodriguez M et al. (2007) T‐box factors: targeting to chromatin and interaction with the histone H3 N‐terminal tail. Pigment Cell Research 20(4): 279–287.

Dias RR, Albuquerque JM, Pereira AC et al. (2007) Holt‐Oram syndrome presenting as agenesis of the left pericardium. International Journal of Cardiology 114(1): 98–100.

Fan C, Duhagon MA, Oberti C et al. (2003) Novel TBX5 mutations and molecular mechanism for Holt‐Oram syndrome. Journal of Medical Genetics 40(3): e29.

Fan C, Liu M and Wang Q (2003) Functional analysis of TBX5 missense mutations associated with Holt‐Oram syndrome. Journal of Biological Chemistry 278(10): 8780–8785.

Fanning AS and Anderson JM (1999) PDZ domains: fundamental building blocks in the organization of protein complexes at the plasma membrane. Journal of Clinical Investigation 103(6): 767–772.

Furniss D, Kan SH, Taylor IB et al. (2009) Genetic screening of 202 individuals with congenital limb malformations and requiring reconstructive surgery. Journal of Medical Genetics 46(11): 730–735.

Garavelli L, De Brasi D, Verri R et al. (2008) Holt‐Oram syndrome associated with anomalies of the feet. American Journal of Medical Genetics Part A 146A(9): 1185–1189.

Garcia‐Moya L, Lapunzina Badia P, Delicado Navaroo A et al. (2006) sindrome de Holt‐Oram:caracterizacion de una nueva mutatcion. Anales de Pediatría 64(6): 578–582.

Garg V, Kathiriya IS, Barnes R et al. (2003) GATA4 mutations cause human congenital heart defects and reveal an interaction with TBX5. Nature 424(6947): 443–447.

Ghosh TK, Packham EA, Bonser AJ et al. (2001) Characterization of the TBX5 binding site and analysis of mutations that cause Holt‐Oram syndrome. Human Molecular Genetics 10(18): 1983–1994.

Ghosh TK, Song FF, Packham EA et al. (2009) Physical interaction between TBX5 and MEF2C is required for early heart development. Molecular and Cellular Biology 29(8): 2205–2218.

Greulich F, Rudat C and Kispert A (2011) Mechanisms of T‐box gene function in the developing heart. Cardiovascular Research 91(2): 212–222.

Gruenauer‐Kloevekorn C and Froster UG (2003) Holt‐Oram syndrome: a new mutation in the TBX5 gene in two unrelated families. Annales de Génétique 46(1): 19–23.

Hatcher CJ, Kim MS, Mah CS et al. (2001) TBX5 transcription factor regulates cell proliferation during cardiogenesis. Developmental Biology 230(2): 177–188.

Heinritz W, Moschik A, Kujat A et al. (2005) Identification of new mutations in the TBX5 gene in patients with Holt‐Oram syndrome. Heart 91(3): 383–384.

Herrmann BG, Labeit S, Poustka A et al. (1990) Cloning of the T gene required in mesoderm formation in the mouse. Nature 343(6259): 617–622.

Hiroi Y, Kudoh S, Monzen K et al. (2001) Tbx5 associates with Nkx2‐5 and synergistically promotes cardiomyocyte differentiation. Nature Genetics 28(3): 276–280.

Holt M and Oram S (1960) Familial heart disease with skeletal malformations. British Heart Journal 22: 236–242.

Kimura H (2013) Histone modifications for human epigenome analysis. Journal of Human Genetics 58(7): 439–445.

Kirk EP, Sunde M, Costa MW et al. (2007) Mutations in cardiac T‐box factor gene TBX20 are associated with diverse cardiac pathologies, including defects of septation and valvulogenesis and cardiomyopathy. American Journal of Human Genetics 81(2): 280–291.

Kispert A and Herrmann BG (1993) The Brachyury gene encodes a novel DNA binding protein. EMBO Journal 12(8): 3211–3220.

Kohlhase J, Schubert L, Liebers M et al. (2003) Mutations at the SALL4 locus on chromosome 20 result in a range of clinically overlapping phenotypes, including Okihiro syndrome, Holt‐Oram syndrome, acro‐renal‐ocular syndrome, and patients previously reported to represent thalidomide embryopathy. Journal of Medical Genetics 40(7): 473–478.

Koshiba‐Takeuchi K, Takeuchi JK, Arruda EP et al. (2006) Cooperative and antagonistic interactions between Sall4 and Tbx5 pattern the mouse limb and heart. Nature Genetics 38(2): 175–183.

Krause A, Zacharias W, Camarata T et al. (2004) Tbx5 and Tbx4 transcription factors interact with a new chicken PDZ‐LIM protein in limb and heart development. Developmental Biology 273(1): 106–120.

Kulisz A and Simon HG (2008) An evolutionarily conserved nuclear export signal facilitates cytoplasmic localization of the Tbx5 transcription factor. Molecular and Cellular Biology 28(5): 1553–1564.

Lappalainen T, Montgomery SB, Nica AC et al. (2011) Epistatic selection between coding and regulatory variation in human evolution and disease. American Journal of Human Genetics 89(3): 459–463.

Leconte L, Lecoin L, Martin P and Saule S (2004) Pax6 interacts with cVax and Tbx5 to establish the dorsoventral boundary of the developing eye. Journal of Biological Chemistry 279(45): 47272–47277.

Lee S, Lee JW and Lee SK (2012) UTX, a histone H3‐lysine 27 demethylase, acts as a critical switch to activate the cardiac developmental program. Developmental Cell 22(1): 25–37.

Lehner R, Goharkhay N, Tringler B et al. (2003) Pedigree analysis and descriptive investigation of three classic phenotypes associated with Holt‐Oram syndrome. Journal of Reproductive Medicine 48(3): 153–159.

Lewandowski SL, Janardhan HP, Smee KM et al. (2014) Histone deacetylase 3 modulates Tbx5 activity to regulate early cardiogenesis. Human Molecular Genetics

Li QY, Newbury‐Ecob RA, Terrett JA et al. (1997) Holt‐Oram syndrome is caused by mutations in TBX5, a member of the Brachyury (T) gene family. Nature Genetics 15(1): 21–29.

Lickert H, Takeuchi JK, Von Both I et al. (2004) Baf60c is essential for function of BAF chromatin remodelling complexes in heart development. Nature 432(7013): 107–112.

Martinez‐Garcia M, Lorda‐Sanchez I, Garcia‐Hoyos M et al. (2010) [Holt‐Oram syndrome: study of 7 cases]. Medicina Clinica 135(14): 653–657.

Maurano MT, Humbert R, Rynes E et al. (2012) Systematic localization of common disease‐associated variation in regulatory DNA. Science 337(6099): 1190–1195.

McCulley DJ and Black BL (2012) Transcription factor pathways and congenital heart disease. Current Topics in Developmental Biology 100: 253–277.

McDermott DA, Bressan MC, He J et al. (2005) TBX5 genetic testing validates strict clinical criteria for Holt‐Oram syndrome. Pediatriac Research 58(5): 981–986.

McDermott DA, Fong JC and Basson CT (1993) Holt‐Oram syndrome. In: Pagon RA , Adam MP , Ardinger HH et al. (eds) GeneReviews. Seattle, WA: University of Washington, Seattle University of Washington, Seattle. PMID: 20301290.

Mori AD and Bruneau BG (2004) TBX5 mutations and congenital heart disease: Holt‐Oram syndrome revealed. Current Opinion in Cardiology 19(3): 211–215.

Muller CW and Herrmann BG (1997) Crystallographic structure of the T domain DNA complex of the Brachyury transcription factor. Nature 389(6653): 884–888.

Murakami M, Nakagawa M, Olson EN and Nakagawa O (2005) A WW domain protein TAZ is a critical coactivator for TBX5, a transcription factor implicated in Holt‐Oram syndrome. Proceedings of the National Academy of Sciences of the USA 102(50): 18034–18039.

Muru K, Kalev I, Teek R et al. (2011) A boy with Holt‐Oram syndrome caused by novel mutation c.1304delT in the TBX5 gene. Molecular Syndromology 1(6): 307–310.

Naiche LA, Harrelson Z, Kelly RG and Papaioannou VE (2005) T‐box genes in vertebrate development. Annual Review of Genetics 39: 219–239.

Newbury‐Ecob RA, Leanage R, Raeburn JA and Young ID (1996) Holt‐Oram syndrome: a clinical genetic study. Journal of Medical Genetics 33(4): 300–307.

Patel C, Silcock L, McMullan D, Brueton L and Cox H (2012) TBX5 intragenic duplication: a family with an atypical Holt‐Oram syndrome phenotype. European Journal of Human Genetics 20(8): 863–869.

Pfeufer A, Van Noord C, Marciante KD et al. (2010) Genome‐wide association study of PR interval. Nature Genetics 42(2): 153–159.

Porto MP, Vergani N, Carvalho AC et al. (2010) Novel mutations in the TBX5 gene in patients with Holt‐Oram Syndrome. Genetics and Molecular Biology 33(2): 232–236.

Postma AV, Alders M, Sylva M et al. (2014) Mutations in the T (brachyury) gene cause a novel syndrome consisting of sacral agenesis, abnormal ossification of the vertebral bodies and a persistent notochordal canal. Journal of Medical Genetics 51(2): 90–97.

Postma AV, Van De Meerakker JB, Mathijssen IB et al. (2008) A gain‐of‐function TBX5 mutation is associated with atypical Holt‐Oram syndrome and paroxysmal atrial fibrillation. Circulation Research 102(11): 1433–1442.

Sebe‐Pedros A, Ariza‐Cosano A, Weirauch MT et al. (2013) Early evolution of the T‐box transcription factor family. Proceedings of the National Academy of Sciences of the USA 110(40): 16050–16055.

Showell C, Binder O and Conlon FL (2004) T‐box genes in early embryogenesis. Developmental Dynamics 229(1): 201–218.

Sletten LJ and Pierpont ME (1996) Variation in severity of cardiac disease in Holt‐Oram syndrome. American Journal of Medical Genetics Part A 65(2): 128–132.

Smemo S, Campos LC, Moskowitz IP et al. (2012) Regulatory variation in a TBX5 enhancer leads to isolated congenital heart disease. Human Molecular Genetics 21(14): 3255–3263.

Sotoodehnia N, Isaacs A, De Bakker PI et al. (2010) Common variants in 22 loci are associated with QRS duration and cardiac ventricular conduction. Nature Genetics 42(12): 1068–1076.

Stirnimann CU, Ptchelkine D, Grimm C and Muller CW (2010) Structural basis of TBX5‐DNA recognition: the T‐box domain in its DNA‐bound and ‐unbound form. Journal of Molecular Biology 400(1): 71–81.

Tseng YR, Su YN, Lu FL et al. (2007) Holt‐Oram syndrome with right lung agenesis caused by a de novo mutation in the TBX5 gene. American Journal of Medical Genetics Part A 143A(9): 1012–1014.

Vaughan CJ and Basson CT (2000) Molecular determinants of atrial and ventricular septal defects and patent ductus arteriosus. American Journal of Medical Genetics 97(4): 304–309.

Vianna CB, Miura N, Pereira AC and Jatene MB (2011) Holt‐Oram syndrome: novel TBX5 mutation and associated anomalous right coronary artery. Cardiology in the Young 21(3): 351–353.

Wang C, Cao D, Wang Q and Wang DZ (2011) Synergistic activation of cardiac genes by myocardin and Tbx5. PLoS One 6(8): e24242.

Yagi H, Furutani Y, Hamada H et al. (2003) Role of TBX1 in human del22q11.2 syndrome. Lancet 362(9393): 1366–1373.

Yang J, Hu D, Xia J et al. (2000) Three novel TBX5 mutations in Chinese patients with Holt‐Oram syndrome. American Journal of Medical Genetics 92(4): 237–240.

Zaragoza MV, Lewis LE, Sun G et al. (2004) Identification of the TBX5 transactivating domain and the nuclear localization signal. Gene 330: 9–18.

Further Reading

Mckusick VA and O'neill MJF (1997) T‐BOX5.

Stoll C, Dott B, Alembik Y et al. (2013) Associated malformations among infants with radial ray deficiency. Genetic Counseling 24(2): 223–234.

Sunagawa S, Kikuchi A, Sano Y et al. (2009) Prenatal diagnosis of Holt‐Oram syndrome: role of 3‐D ultrasonography. Congenital Anomalies 49(1): 38–41.

Tsai TC, Lu JK, Choo SL et al. (2012) The paracrine effect of exogenous growth hormone alleviates dysmorphogenesis caused by tbx5 deficiency in zebrafish (Danio rerio) embryos. Journal of Biomedical Science 19: 63.

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Barnett, Phil, and Postma, Alex V(Jun 2014) Molecular Genetics of Holt–Oram Syndrome. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0024329]