- Whole exome sequencing confirmed a de novo pathogenic DHX30 variant in a proband with global developmental delay and identified a novel association with microtia.
- Scoping review of 51 individuals shows predominantly de novo DHX30 variants with core features: motor delay, intellectual disability, hypotonia, feeding difficulties, absent expressive language.
- Study underscores the clinical utility of WES for diagnosing global developmental delay and recommends ongoing WES reanalysis for evolving variant interpretation.
J Intellect Disabil Res. 2026 Sep 6. doi: 10.1111/jir.70169. Online ahead of print.
ABSTRACT
BACKGROUND: Whole exome sequencing (WES) has improved diagnostic rates for neurodevelopmental disorders (NDDs) while introducing challenges in novel variant interpretation. DHX30-related NDD (DHX30-NDD) is a recently described condition with an evolving phenotypic spectrum.
OBJECTIVES: To expand the understanding of the DHX30-NDD genotype-phenotype spectrum by integrating a case-based WES interpretation with a scoping review.
METHODS: We performed comprehensive genetic analysis (karyotyping, microarray, WES) on a proband with global developmental delay (GDD). A systematic literature search of PubMed/MEDLINE, Scopus and Google Scholar from database inception to April 2026 identified 10 publications including 51 individuals with DHX30-NDD. Clinical and genetic data were extracted to characterize the genotype-phenotype spectrum.
RESULTS: The proband presented with GDD and right microtia, harbouring a de novo heterozygous pathogenic DHX30 missense variant (c.1478G > A; p.Arg493His), confirming DHX30-NDD. To our knowledge, this is the first reported individual with DHX30-NDD and microtia. The scoping review confirmed DHX30 variants are formed predominantly de novo and affected both sexes (22 males; 29 females). Hallmark manifestations were motor delay (50/51; 98.0%), GDD/ID (48/49; 98.0%), hypotonia (48/51; 94.1%), feeding difficulties (38/51; 74.5%), ataxia (17/23; 73.9%), abnormal brain imaging (36/49; 73.5%) and absent expressive language (35/48; 72.9%). Digital anomalies (31/51; 60.8%), eye anomalies (28/51; 54.9%), autistic behaviours (24/44; 54.5%), sleep disturbances (26/51; 51.0%), joint hypermobility (25/51; 49.0%), microcephaly (23/51; 45.1%) and ear anomalies (22/51; 43.1%) were also frequent.
CONCLUSIONS: This study potentially expands the phenotypic spectrum of DHX30-NDD, highlights the clinical utility of WES for diagnosing GDD and underscores the importance of ongoing WES reanalysis for evolving variant interpretation.
PMID:42702753 | DOI:10.1111/jir.70169
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