Identification of novel RIPK4 variants in a Chinese patient with Arthrogryposis Multiplex Congenita (AMC).

Background: Arthrogryposis multiplex congenita (AMC) is a congenital disorder characterized by multiple joint involvement, primarily affecting limb mobility and leading to various tissue contractures. Variations in the RIPK4 gene may impact connective tissues, thereby resulting in a spectrum of malformations. This study aimed to identify the genetic etiologies of AMC patients and provide genetic testing information for further diagnosis and treatment of AMC.

Methods: We recruited a Chinese female patient with hand-related AMC and her family members. Whole-exome sequencing (WES) was employed to determine the genetic etiologies of the patient's disease. The pathogenic mechanisms of the identified variations were analyzed using protein tolerance profiling and modeling.

Results: We identified two novel RIPK4 variants (c.1354G > A, p.E452K; c.1558A > T, p.T520S). Pathogenicity studies indicated that the c.1354G > A, p.E452K variant changed the charge from negative to positive and altered the chemical properties from acidic to alkaline, potentially significantly affecting protein function.

Conclusions: We reported the discovery of two novel RIPK4 variants (c.1354G > A, p.E452K; c.1558A > T, p.T520S) in a Chinese AMC female patient's family. Our study enhances the genetic repository for AMC and highlights the pathogenicity of RIPK4 variants, underscoring the significance of comprehensive management for genetic-related diseases, particularly the critical roles of prenatal diagnosis and genetic counseling.

Trial registration: The research protocol received approval from the Ethics Review Committee of Xiangya Hospital of Central South University in China (approval number: 202103427), registered in March 2021, with all participants providing duly signed informed consent forms.