Holt‐Oram syndrome in four half‐siblings with unaffected parents: brief clinical report

The Holt‐Oram syndrome was diagnosed in four offspring of three mothers and the same unaffected father. One additional child lacked the characteristic clinical features of the Holt‐Oram syndrome. In contrast to the general autosomal dominant inheritance with complete penetrance, our observation suggests a paternal mutation, resulting in mosaicism, probably restricted to the germline.