P799: Using the single-cell transcriptome to facilitate molecular diagnosis of retinal dystrophy: A case report

Furthermore, Pirmoradi et al have highlighted that alterations in the ARPC4 gene affect critical signaling pathway interactions, potentially contributing to the development of complex conditions, including metabolic and cardiovascular diseases.These findings underscore the importance of ARPC4 as a target for understanding the pathophysiology of multifactorial diseases. Conclusion:We report a new case of a patient with a recurrent de novo variant in the ARPC4 gene and a neurodevelopmental disorder characterized by microcephaly, mild motor delay, and significant language impairment.This case highlights the importance of ARPC4 in understanding the mechanisms underlying complex diseases, including neurological and cardiovascular conditions.It also emphasizes the gene's potential as a biomarker and therapeutic target.However, further research is needed to fully elucidate the functional interactions of this gene and its clinical applicability in hereditary and complex diseases.Introduction: The ARPC4 gene encodes one of the subunits of the Arp2/3 complex, which is essential for regulating actin cytoskeleton dynamics.This complex plays a critical role in cell migration and proliferation, fundamental processes in cellular development and response to external stimuli.Pathogenic variants in the ARPC4 gene have been associated with rare genetic conditions and contribute to the development of complex diseases.Due to its fundamental role in maintaining cellular architecture, variants or dysregulation in ARPC4 expression can result in diverse pathological phenotypes, including autoimmune, cardiovascular, and neurological disorders.Case Presentation: We report the case of a 3-year-and-6-month-old male patient, the son of a young, non-consanguineous couple, referred for neurological evaluation due to delayed neuropsychomotor development, sleep disturbances, and agitation.The patient was born via cesarean section at 36 weeks and 6 days of gestation due to preeclampsia, premature rupture of membranes, and signs of acute fetal distress.His birth weight was 2690 g (36th percentile), and his APGAR scores were 9/10.During the neonatal period, he presented with mild respiratory distress requiring one day of oxygen therapy and underwent phototherapy for four days.At 12 months of age, significant motor delay was identified; the patient was unable to stand with support or crawl.At 2 years, additional developmental delays were observed, including cognitive and language delays, along with agitation and irritability.Risperidone treatment was initiated at that time.Following this period, the patient produced only a few words and predominantly relied on non-verbal communication, remaining fully dependent on caregivers for daily activities.Diagnostic Workup: Physical examination