Case Report: Blepharophimosis and Ptosis as Leading Dysmorphic Features of Rare Congenital Malformation Syndrome With Developmental Delay - New Cases With TRAF7 Variants

The structure of TRAF7 coiled-coil trimer provides insight into its function in zebrafish embryonic development

TRAF7 serves as a crucial intracellular adaptor and E3 ubiquitin ligase involved in signal transduction pathways, contributing to immune responses, tumor progression, and embryonic development. Somatic mutations within the coiled-coil (CC) domain and WD40 repeat domain of TRAF7 could cause brain tumors, while germline pathogenic mutations contribute to severe developmental abnormalities. However, the precise molecular mechanism underlying TRAF7 involvement in embryonic development remains unclear. In this study, we employed zebrafish as an in vivo model system. TRAF7 knock down caused defects in zebrafish embryonic development. We determined the crystal structure of TRAF7 CC domain at 3.3 Å resolution and found that the CC region trimerization was essential for TRAF7 functionality during zebrafish embryonic development. Additionally, disease-causing mutations in TRAF7 CC region could impair the trimer formation, consequently impacting early embryonic development of zebrafish. Therefore, our study sheds light on the molecular mechanism of TRAF7 CC trimer formation and its pivotal role in embryonic development.

The First Korean Case with Cardiac, Facial, and Digital Anomalies with Developmental Delay Caused by De Novo TRAF7 p.Arg655Gln Variant

TRAF7-related disorders represent some of the rarest inherited disorders, exhibiting clinical features that overlap with cardiac, facial, and digital anomalies with developmental delay (CAFDADD) syndrome, as well as blepharophimosis-mental retardation syndrome (BMRS). A 36-year-old male, presenting with total blindness, blepharophimosis, and intellectual disability, was admitted for the assessment of resting dyspnea several months previously. He had a history of being diagnosed with obstructive sleep apnea (OSA). Transesophageal and transthoracic echocardiography unveiled right ventricular dilatation without significant pulmonary hypertension, bicuspid aortic valve with aortic root aneurysm, and aortic regurgitation in the proband. Sanger sequencing identified a de novo TRAF7 variant (c.1964G>A; p.Arg655Gln). Subsequently, aortic root replacement using the Bentall procedure was performed. However, despite the surgery, he continued to experience dyspnea. Upon re-evaluating OSA with polysomnography, it was discovered that continuous positive airway pressure support alleviated his symptoms. The underlying cause of his symptoms was attributed to OSA, likely exacerbated by the vertebral anomaly and short neck associated with CAFDADD syndrome. Clinicians should be attentive to the symptoms associated with OSA as it is a potentially serious medical condition in patients with TRAF7 variants.

Prenatal diagnosis of a germline variant in TRAF7: Importance of accessibility to prenatal exome sequencing in cases of structural fetal anomalies

Diagnosis of a pathogenic germline TRAF7 missense variant (c.1555 C > T, p.L519F) made on a prenatal basis by exome sequencing (ES) performed on chorionic villi. This case highlights the importance of both higher-level prenatal ultrasounds and the accessibility of ES in making genetic diagnoses in making pregnancy management decisions.