Christianson Syndrome (CS) is a rare X-linked condition with cognitive dysfunction.

Chromosome: Xq26.3

Gene: SLC9A6 (sodium/hydrogen exchanger 6; solute carrier family 9, member 6)


Inheritance: X-linked


Clinical features:

(1) cognitive dysfunction with developmental delay and intellectual disability

(2) behavioral problems (autism spectrum, hyperactivity)

(3) seizures

(4) truncal ataxia

(5) postnatal microcephaly

(6) abnormal eye movements (convergent strabismus, esotropia, abnormal horizontal eye movements)

(7) hypotonia

(8) oropharyngeal dysphagia with difficult feeding

(9) constipation

(10) regression with loss of acquired skills such as ambulation and independent feeding


Facial features are nondysmorphic.


Females may be affected by findings tend to minimal to mild.

To read more or access our algorithms and calculators, please log in or register.