A novel de novo nonsense mutation in ZC4H2 causes Wieacker‐Wolff Syndrome

BACKGROUND: Wieacker‐Wolff syndrome (WWS) is a congenital X‐linked neuromuscular disorder, which was firstly reported in 1985. Zinc finger C4H2‐type containing (ZC4H2) gene has been found to be associated with the disease pathogenesis. However, the underlying mechanism remains elusive. METHODS: Whole‐exome sequencing was performed to identify the mutations. Expression plasmids were constructed and cell culture and immune‐biochemical assays were used to examine the effects of the mutation. RESULTS: We reported a female patient with classical symptoms of WWS and discovered a novel nonsense heterozygous mutation (p.R67X; c.199C>T) in ZC4H2 gene in the patient but not in her parents. The mutation resulted in a 66 amino‐acid truncated ZC4H2 protein. The mutation is located in the key helix domain and it altered the subcellular locations of the mutant ZC4H2 protein. X‐chromosome inactivation (XCI) pattern analysis revealed that the XCI ratio of the proband was 22:78. CONCLUSION: Female heterozygous carriers with nonsense mutation with a truncated ZC4H2 protein could lead to the pathogenesis of Wieacker‐Wolff syndrome and our study provides a potential new target for the disease treatment.