biostudies-literatureLi XNational Natural Science Foundation of Chinae11774https://www.ebi.ac.uk/biostudies/studies/S-EPMC9699963biostudies-literatureUnknown8(11)Holt-Oram syndrome (HOS) is a rare autosomal dominant disorder characterized by skeletal abnormalities of the upper limbs and often cardiac malformations. We investigated a Chinese family with clinical features suggestive of HOS. Clinical examinations revealed that both the proband and his father had anomalies in the upper limbs and heart. The proband had a rare common atrium. Whole exome sequencing detected a novel small-insertion mutation (c.680_681insCTGAGAATAAT; p.Ile227fs∗) in <i>TBX5</i> gene, the known disease gene for HOS. The mutation cosegregated with HOS phenotypes in the family and was predicted to cause frameshift, resulting in a truncated protein. In this study, we described a rare HOS case with common atrium. A novel small-insertion in <i>TBX5</i> coding sequence was identifHeliyonIdentification of a novel <i>TBX5</i> mutation in a Chinese family with rare symptoms of Holt-Oram syndrome.PMC969996381972038Li XWu JZhu MDing XLi YLi JNong TShi WXu HYuan ZfalseIdentification of a novel <i>TBX5</i> mutation in a Chinese family with rare symptoms of Holt-Oram syndrome.Holt-Oram syndrome (HOS) is a rare autosomal dominant disorder characterized by skeletal abnormalities of the upper limbs and often cardiac malformations. We investigated a Chinese family with clinical features suggestive of HOS. Clinical examinations revealed that both the proband and his father had anomalies in the upper limbs and heart. The proband had a rare common atrium. Whole exome sequencing detected a novel small-insertion mutation (c.680_681insCTGAGAATAAT; p.Ile227fs∗) in <i>TBX5</i> gene, the known disease gene for HOS. The mutation cosegregated with HOS phenotypes in the family and was predicted to cause frameshift, resulting in a truncated protein. In this study, we described a rare HOS case with common atrium. A novel small-insertion in <i>TBX5</i> coding sequence was identif2022-01-01T00:00:00Z2022 Nov2025-04-18T20:32:34.411Z2025-04-07T08:25:11.17ZS-EPMC96999633644424510.1016/j.heliyon.2022.e11774