Is Holt-Oram syndrome inherited ?
How is Holt-Oram syndrome inherited? Holt-Oram syndrome (HOS) is inherited in an autosomal dominant manner. This means that having only one changed (mutated) copy of the responsible gene in each cell is enough to cause signs and symptoms of the condition. In most cases, the mutation in the gene occurs for the first time in the affected person and is not inherited from a parent. When a mutation occurs for the first time, it is called a de novo mutation. This is what typically occurs when there is no family history of the condition. A de novo mutation is due to a random change in the DNA in an egg or sperm cell, or right after conception. In some cases, an affected person inherits the mutated copy of the gene from an affected parent. In these cases, the symptoms and severity can differ from those of the affected parent.  When a person with an autosomal dominant condition has children, each child has a 50% (1 in 2) risk to inherit the condition.