Waardenburg syndrome (WS) is a rare genetic disorder characterized by congenital sensorineural hearing loss and pigmentary abnormalities, accounting for 2-5% of congenital deafness. While molecular testing is the diagnostic gold standard, clinical recognition remains crucial in low-resource or conflict-affected environments where specialized services are unavailable. We report a Syrian male in his early 20s who presented to the otorhinolaryngology clinic seeking exemption from military service, citing long-standing right-sided hearing loss. The patient and his family had never pursued medical evaluation for his pigmentary features or hearing problem. Examination revealed a white forelock, heterochromia iridis, synophrys, broad nasal root, and dystopia canthorum (W Index 2.2). Pure-tone audiometry demonstrated severe unilateral sensorineural hearing loss. Systematic neurological, ophthalmological, and musculoskeletal assessments were normal. Due to the lack of access to genetic testing, a clinical diagnosis of WS type I was made, and the patient was referred for genetic counseling. This case highlights diagnostic challenges in conflict-affected, resource-limited settings. Despite striking phenotypic features, the patient remained undiagnosed until adulthood. Missed opportunities included the absence of childhood hearing screening, delayed recognition of pigmentary signs, and a lack of educational or psychosocial support. Literature indicates that phenotypic diagnosis is reliable when multiple major criteria are present, yet diagnostic delays significantly affect quality of life. This report underscores the importance of timely recognition of WS in low-resource contexts. Strengthening primary care awareness, implementing basic audiological and pigmentary screening, and integrating psychosocial support may help mitigate diagnostic delays and improve long-term outcomes for patients with rare genetic disorders.

Waardenburg syndrome type 1 (WS1) is a rare autosomal dominant disorder characterized by congenital sensorineural hearing loss and facial dysmorphisms. PAX3 mutations are a known genetic cause. This study investigated a novel PAX3 mutation in a Chinese Yugur family and assessed long-term auditory outcomes after cochlear implantation. Whole-exome and Sanger sequencing were used to identify causative variants, followed by bioinformatic analyses to predict pathogenicity. Auditory and speech rehabilitation were evaluated over a 7-year follow-up. A novel heterozygous frameshift mutation in PAX3 (c.788dup, p.Gln264ThrfsTer5) was identified and confirmed to be de novo. Structural modeling indicated disruption of a conserved domain, supporting its pathogenic role. The proband achieved excellent auditory and speech recovery and successfully integrated into mainstream education. This study expands the mutation spectrum of PAX3 and provides evidence supporting the pathogenicity of the c.788dup variant. It also confirms the long-term benefit of cochlear implantation and rehabilitation in WS1-related hearing loss.

Waardenburg syndrome (WS) is an auditory-pigmentary syndrome characterized by hair pigmentary abnormalities, pigmentary abnormalities of the iris, and congenital hearing loss. Type 1 associated with dystopia canthorum is caused by mutations in PAX3 gene which codes for DNA-binding transcription factor involved in neural crest border induction at the neural plate. A 41-year-old male patient of consanguineous Egyptian parents presenting with progressive nyctalopia and field constriction underwent complete ophthalmological examination. Additionally, color fundus photography, fundus autofluorescence (FAF), spectral domain optical coherence tomography (SD-OCT) of the macula, full field electroretinogram (ERG), visual field perimetry and B-scans were obtained. Whole-exome sequencing (WES) was performed from a peripheral blood sample followed by bioinformatics analysis. A novel mutation in PAX3 gene c.688C>A was identified by WES consistent with a diagnosis of Waardenburg syndrome (WS) type 1. Further bioinformatic analysis of WES raw data identified another novel mutation in CFAP410 c.293C>T confirming the associated RP diagnosis. To the best of our knowledge, this is the first report of RP in a WS patient. We are reporting novel mutations in PAX3 and CFAP410 genes and expanding number of cases of non-syndromic retinal degeneration in CFAP410- associated retinopathy.