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

Abstract

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.

Keywords: Arthrogryposis multiplex congenita; Wieacker-Wolff syndrome; X-chromosome inactivation; ZC4H2; nonsense mutation.