The Holt-Oram Syndrome (HOS) can be diagnosed if certain criteria are met.


Synonym: heart and hand syndrome


Chromosome: 12q24.1

Gene: TBX5 (T-Box 5)


Inheritance: autosomal dominant (parents affected)


Clinical features - all of the following:

(1) upper limb malformation - one or more of the following:

(1a) malformation of the radius

(1b) malformation of the thenar bone

(1c) malformation of a carpal bone

(2) congenital heart malformation such as

(2a) osteum secundum atrial septal defect (OS ASD)

(2b) ventricular septal defect (VSD)

(2c) conotruncal malformation

(3) cardiac conduction defect such as

(3a) sinus bradycardia

(3b) AV block - first, second or third degree

(4) exclusion of other congenital malformations (to ulnar ray only, kidney, vertebrae, ear, eye, anus, and/or craniofacies)



• The VSD may involve the muscular trabeculated septum.

• The cardiac conduction defect may be diagnosed at birth or be recognized at an older age.

• Atrial fibrillation may complicate complete AV block.


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