Is Noonan syndrome inherited ?
How is Noonan syndrome inherited? Noonan syndrome is inherited in an autosomal dominant manner. This means that having one changed (mutated) copy of the responsible gene in each cell is enough to cause the condition. Each child of a person with Noonan syndrome has a 50% (1 in 2) chance to inherit the condition. In some cases, the condition is inherited from an affected parent. Because the features of the condition can vary and may be very subtle, many affected adults are diagnosed only after the birth of a more obviously affected infant. In other cases, the condition is caused by a new mutation occurring for the first time in the affected person.