Based on the presentation of the proband and other reported patients with whole gene deletions, we provide further evidence that L1CAM whole gene deletions result in L1 syndrome with a severe phenotype, deletions of PDZD4 do not cause additional manifestations, and that X-linked nephrogenic diabetes insipidus reported in a subset of patients with large L1CAM deletions results from the loss of AVPR2.
Taken together, these findings strongly suggest that inappropriate expression of PDZK4 might play an important role in the proliferation of SS cells and that the gene might be a suitable molecular target for designing of novel drugs to treat SS patients.