Robinow syndrome is a rare genetic disorder that affects the development of multiple systems. Due to its low prevalence and diversity of phenotypic presentation it has been challenging to definitively characterize features of Robinow syndrome.
We performed DNA extraction, whole-exome sequencing analysis, and mutation analysis of DVL1 to obtain genetic data on the patient. We subsequently analyzed the patient\'s clinical and genetic data.
The proband was a 3-month-old female infant who suffered from significant global developmental delay and metabolic disorder. The main clinical manifestations included facial dysmorphisms, bilateral dislocation of the hip joint, and hearing impairment. Whole-exome sequencing of the patient\'s DNA revealed a heterozygous mutation of c.1620delC in DVL1. Analysis with the MutationTaster application indicated that both were pathogenic (probability = 1), causing frameshift mutations affecting 107 amino acids (p.S542Vfs*107). Significant structural changes were identified in the amino acid sequence after the WNT signaling-related DEP domain site was predicted using the AlphaFold Protein structure database. The stability of the three main domains was then evaluated using SWISS-MODEL, and indicated that the mutation did not alter the DIX, PDZ, or DEP domain sequences. Because all reported pathogenic mutations were located near the DEP domain, we speculated that structural changes around the DEP domain may have impaired WNT domain function and WNT signaling, resulting in Robinow syndrome.
The present case suggests that molecular genetic screening is useful for the diagnosis of developmental disorders, particularly in children with a positive family history. In the current patient all the related pathological variants were located within a narrow locus. This report expands the known manifestations of Robinow syndrome and contributes to refinement of its molecular basis.

BACKGROUND: Autosomal recessive Robinow syndrome (ARRS) is a rare genetic disorder, which affects the development of multiple systems, particularly the bones.
OBJECTIVE: The aim of this study was to investigate the genetic cause of a ARRS fetus and to evaluate the reliability of whole-exome sequencing (WES) in prenatal diagnosis on cases with indistinguishable multiple malformation.
METHODS: Clinical and ultrasonic evaluations were conducted on the fetus, and multiplatform genetic techniques were used to identify the variation responsible for RS. The pathogenicity of the novel variation was evaluated by in silico methods. Western blotting (WB) and immunohistochemistry (IHC) were performed on fetal tissues after the fetus\' stillbirth and postabortal autopsy.
RESULTS: A compound heterozygous variation consisting c.613C > T and c.904C > T in ROR2 gene was identified. In silico prediction suggested that c.904C > T was a deleterious variant. IHC result demonstrated that ror2 expression level of the proband in osteochondral tissue significantly increased comparing with that of the control sample.
CONCLUSIONS: For the first time in Chinese population, we characterized a novel variation in ROR2 gene causing ARRS. This study extended the mutation spectrum of ARRS and provided a promising strategy for prenatal diagnosis of cases with ambiguous multiple deformities.