BACKGROUND: The Holt-Oram Syndrome (HOS) or the Heart-Hand syndrome is consideredas an overt autosomal hereditary disease with a complete influential effect and variableexpression that emerges due to a genetic mutation. It can be vividly characterized by heartdisorders and deficiencies in hand structure. Despite the existing genetic heterogeneity, thevariable integration between HOS and the T-BX5 gene from the T-BOX Gene Complex has beenobserved during which various mutations have been reported in the affected patients. The TBOXGene Complex is located on chromosome 12 (12 q 24.1), and is able to encode a copyingfactor. That has a conservative motive with 180 amino acids. The deficiencies in only 1/3 ofpatients have been observed caused by the mutation of this gene.CASE REPORT: This case was a 10-year-old child with hand disorders, incompletegrowth of clavicle, moving problems in elbow joint and shoulder, disorder in ventricle andauricle walls. The disease was diagnosed as HOS, based on clinical examination and drawing thefamily tree diagram. It was impossible to investigate molecular mutation due to inaccessibilityto the patient.CONCLUSION: By investigating the family members and their deficiencies and imagingdisorder variables according to different reports as well as parents’ state of health, the HOS canbe defined as an overt heredity resulting from a new mutation in the germinating layer of sexualcells in one of the parents. There is a weak possibility that the disease results from a mosaicmutation in the male parent’s testicle or the female parent’s ovum. In this case, the probabilityfor the disease to be repeated in parents’ next children will be guessed between 1 and 50%.Keywords: Holt-Oram Syndrome, Hand- Heart Syndrome, T-BOX