Identification of a novel homozygous RAB3GAP1 variant associated with Warburg micro syndrome type 1 in a Moroccan patient and a literature review

Diagnosing patients with syndromic neurodevelopmental disorders presents a significant challenge for clinicians due to the considerable clinical and genetic heterogeneity associated with these rare conditions. The aim of this study was to determine the genetic cause of a Moroccan patient presenting with eye anomalies, hypogonadism, craniofacial dysmorphism and neurodevelopmental abnormalities. Whole exome sequencing (WES) identified a novel homozygous nonsense variant c.2704C > T (p.Gln902Ter) in the RAB3GAP1 gene associated with two clinically similar syndromes (Martsolf syndrome (MS) and Warburg micro syndrome type 1 (WARBM1)). Comparison of the clinical features of the patient with those of MS and WARBM1 syndromes led to the diagnosis of WARBM1. In summary, this report expands the mutational spectrum associated with WARBM1, highlights the diagnostic challenges of syndromic neurodevelopmental disorders and underlines the role of WES in establishing an accurate diagnosis, thereby enabling appropriate clinical management.