Expanding the clinical phenotype of patients with a ZDHHC9 mutation.

In 2007, 250 families with X-linked intellectual disability (XLID) were screened for mutations in genes on the X-chromosome, and in 4 of these families, mutations in the ZDHHC9 gene were identified. The ID was either isolated or associated with a marfanoid habitus. ZDHHC9 encodes a palmitoyl transferase that catalyzes the posttranslational modification of NRAS and HRAS. Since this first description, no additional patient with a ZDHHC9 mutation has been reported in the literature. Here, we describe a large family in which we identified a novel pathogenic ZDHHC9 nonsense mutation (p.Arg298*) by parallel sequencing of all X-chromosome exons. The mutation cosegregated with the clinical phenotyp…