Background
Holt-Oram syndrome, also called heart-hand syndrome, is an inherited disorder characterized by abnormalities of the upper limbs and heart. Holt and Oram first described this condition in 1960 in a 4-generation family with atrial septal defects and thumb abnormalities.[1]
Pathophysiology
The syndrome is inherited as an autosomal dominant trait that is completely penetrant. The disease is due to mutations in the transcription factor TBX5, which is important in the development of both the heart and upper limbs. The pathophysiologic sequelae are a direct result of malformations of the heart and upper limbs. No contributory environmental factors are known.[2]
Upper limb involvement
Although the clinical manifestations are variable, upper limb abnormalities are always present. Abnormalities may be unilateral or bilateral and asymmetric and may involve the radial, carpal, and thenar bones. Aplasia, hypoplasia, fusion, or anomalous development of these bones produces a spectrum of phenotypes, including triphalangeal or absent thumbs. Occasionally, upper limb malformation can be sufficiently severe to produce phocomelia (a malformation in which the hands are attached close to the body); this has been termed pseudothalidomide syndrome. The most prevalent findings in persons with Holt-Oram syndrome are malformations or fusions of the carpal bones. Carpal bone abnormalities are the only findings present in every affected individual, although these anomalies may be evident only radiographically in some patients.
Cardiac involvement
Approximately 75% of patients have some cardiac abnormality. In most patients, the abnormality is either an atrial septal defect (ASD) or a ventricular septal defect (VSD), which varies in number, size, and location. ASDs are usually of the secundum variety, while VSDs tend to occur in the muscular trabeculated septum. Cardiac anomalies also may include cardiac conduction defects such as progressive atrioventricular block and atrial fibrillation.[3, 4] These anomalies are frequently present even in the absence of septal defects.
Epidemiology
Frequency
United States
Holt-Oram syndrome is the most common form of heart-hand syndrome, with prevalence estimated at 0.95 cases per 100,000 total births. Approximately 85% of cases are attributed to new mutations.
Mortality/Morbidity
Structural lesions are present at birth. Prognosis depends on the severity of the cardiac lesions.
- Significant intracardiac shunts can be associated with sudden death or the development of pulmonary hypertension and Eisenmenger syndrome.
- The first clinical manifestation of the disease may be heart failure, cardiac arrhythmias (including heart block), or infective endocarditis.
- Considerable physical and psychologic morbidity may be associated with limb abnormalities, particularly in severe cases.
Sex
Holt-Oram syndrome has no sexual predilection.
Age
- A congenital disease, Holt-Oram syndrome is present at birth. Subtle limb involvement may not become clinically apparent until later in life when the cardiac symptoms of the disease manifest or when an individual has a child with a more severe presentation of the syndrome.
- Cardiac conduction disease is progressive with aging.
- Middle-aged individuals often present with significant atrioventricular block or atrial fibrillation.
HOLT M, ORAM S. Familial heart disease with skeletal malformations. Br Heart J. Apr 1960;22:236-42. [Medline].
Basson CT, Huang T, Lin RC, et al. Different TBX5 interactions in heart and limb defined by Holt-Oram syndrome mutations. Proc Natl Acad Sci U S A. Mar 16 1999;96(6):2919-24. [Medline].
McDermott DA, Hatcher CJ, Basson CT. Atrial Fibrillation and Other Clinical Manifestations of Altered TBX5 Dosage in Typical Holt-Oram Syndrome. Circ Res. Sep 26 2008;103(7):e96. [Medline].
Cerbai E, Sartiani L. Holt-oram syndrome and atrial fibrillation: opening the (T)-box. Circ Res. Jun 6 2008;102(11):1304-6. [Medline].
Basson CT, Cowley GS, Solomon SD, et al. The clinical and genetic spectrum of the Holt-Oram syndrome (heart-hand syndrome). N Engl J Med. Mar 31 1994;330(13):885-91. [Medline].
Basson CT, Solomon SD, Weissman B, et al. Genetic heterogeneity of heart-hand syndromes. Circulation. Mar 1 1995;91(5):1326-9. [Medline].
McDermott DA, Bressan MC, He J, Lee JS, Aftimos S, Brueckner M. TBX5 genetic testing validates strict clinical criteria for Holt-Oram syndrome. Pediatr Res. Nov 2005;58(5):981-6. [Medline].
Pete B, Harmath A, Szigeti Z, Papp C, Hajdú J. [Holt-Oram syndrome: genetic counseling and diagnosis with prenatal ultrasonography]. Orv Hetil. Nov 18 2007;148(46):2173-6. [Medline].
Sunagawa S, Kikuchi A, Sano Y, Kita M, Ono K, Horikoshi T, et al. Prenatal diagnosis of Holt-Oram syndrome: role of 3-D ultrasonography. Congenit Anom (Kyoto). Mar 2009;49(1):38-41. [Medline].
He J, McDermott DA, Song Y, Gilbert F, Kligman I, Basson CT. Preimplantation genetic diagnosis of human congenital heart malformation and Holt-Oram syndrome. Am J Med Genet A. Apr 1 2004;126A(1):93-8. [Medline].
Warnes CA, Williams RG, Bashore TM, Child JS, Connolly HM, Dearani JA, et al. ACC/AHA 2008 Guidelines for the Management of Adults with Congenital Heart Disease: Executive Summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (writing committee to develop guidelines for the management of adults with congenital heart disease). Circulation. Dec 2 2008;118(23):2395-451. [Medline].
Caglayan AO, Koklu E, Saatci C, Gunes T, Ozkul Y, Narin N, et al. Holt-Oram syndrome in two generations with translocation t(9;15)(p12;q11.2). Ann Saudi Med. May-Jun 2008;28(3):209-12. [Medline].
Saura D, Campos JV, Villegas M, Picó F, de la Morena G, Valdés-Chávarri M. Heart-hand syndrome. Int J Cardiol. Sep 16 2008;129(1):e7-9. [Medline].
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