Clinical Guidance

SLC39A8-CDG is characterized by a severe, primarily neurologic phenotype with developmental delay, intellectual disability, muscular hypotonia, and variable additional neurologic symptoms including dyskinetic movements and spasticity. To date, 15 individuals have been identified with pathogenic variants in SLC39A8 [, , , , ]. The following description of the phenotypic features associated with this condition is based on these reports. Table 2. SLC39A8-CDG: Frequency of Select Features

Diagnostic Criteria

Suggestive Findings

SLC39A8-CDG should be suspected in probands with the following clinical, laboratory, imaging, and family history findings.

Clinical findings

• Mild-to-profound developmental delay and/or intellectual disability

• Generalized hypotonia of infancy

Management Guidelines

No clinical practice guidelines for SLC39A8-CDG have been published. Evaluations Following Initial Diagnosis To establish the extent of disease and needs in an individual diagnosed with SLC39A8-CDG, the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended. Table 4. Recommended Evaluations Following Initial Diagnosis in Individuals with SLC39A8-CDG

Surveillance Guidelines

To monitor existing manifestations, the individual's response to supportive care, and the emergence of new manifestations, the evaluations summarized in are recommended. Table 6. Recommended Surveillance for Individuals with SLC39A8-CDG