Home  /  Possible test results

Possible test results


There are four different gene lengths, which means there are four possible results of the DNA test for women.

Woman’s test result Is there a chance of having a child with fragile X syndrome? Are there health concerns?
Short gene length
Normal
Extremely low chance. All children will inherit the short gene. None.
Intermediate gene length
Grey zone
Extremely low chance. Each child has a 50% (1 in 2) chance of inheriting the intermediate gene. There is also a chance that the intermediate gene will increase to the medium gene. If this occurs the child will be a carrier of fragile X syndrome. Unlikely to be affected by any of the clinical features of fragile X syndrome.
Not yet clear if there is a risk of POI or FXTAS.
Medium gene length
Carrier of FXS
Also called premutation
Yes. Each child will have a 50% (1 in 2) chance of inheriting the medium gene and being a carrier of fragile X syndrome. There is a chance that the medium gene will increase to the long gene (affected). If this occurs the child will have fragile X syndrome. Unlikely to be affected by any of the clinical features of FXS.
1 in 5 risk of POI
A chance of developing FXTAS.
Long gene length
Affected with FXS
Also called full mutation
Yes. Each child has a 50% (1 in 2) chance of inheriting the long gene (affected). If this occurs the child will have fragile X syndrome. May be affected by one or more of the clinical features of FXS.