Abstract

Background: Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder in which genetic factors play an important role. This study aimed to describe selected clinical characteristics and characterize the spectrum of genetic variants detected in Vietnamese children with ASD.

Methods: A cross-sectional descriptive study was conducted in 107 children with ASD at the Pediatric Center, Hue Central Hospital, from October 2024 to April 2026. Children were diagnosed according to DSM-5 criteria. DNA extracted from saliva samples was analyzed using genome-wide SNP genotyping with the high-resolution GFWv3 array, which includes more than 800,000 SNP markers; selected variants were confirmed by Sanger sequencing and ARMS-PCR.

Results: Males accounted for 76.6% of participants, and the mean age at first recognition of ASD-related symptoms was 29.0 ± 8.0 months. Delayed or absent language development was observed in 96.3%, lack of eye contact in 90.7%, and failure to respond to their name in 86.0%; 82.2% were classified as having severe autism according to CARS, and 81.6% had a developmental quotient (DQ) ≤70. Twenty-eight of 107 children (26.2%) had at least one genetic variant detected in the study. A total of 33 variants across 24 genes were identified. Variants in FAM98C and SRD5A2 were each identified in three children, whereas variants in ATP7B, PMM2, and PRNP were each identified in two children.

Conclusion: Among the 107 children with ASD, 28 (26.2%) had at least one genetic variant detected in the genes analyzed, with 33 variant findings across 24 genes, reflecting substantial genetic heterogeneity. The findings provide descriptive data on the spectrum of variants identified in Vietnamese children with ASD; may detect variants relevant to other genetic disorders; and may support consideration of genetic counseling in appropriate cases.