Identification of novel ATRX mutations in Chinese patients with ATRX syndrome related intellectual disability/developmental delay

Abstract Background Intellectual disability/developmental delay (ID/DD) is a kind of neurodevelopmental disorders of which the genetic etiologies are to be clarified in majority of the patients. The features of ID/DD patients with hemizygous variants in ATRX in China remains unclear due to the rare reports in worldwide.Methods Clinical data of six Chinese pedigrees with hemizygous variants in ATRX and ID/DD was collected. The information of physical examination, blood tests, metabolism screening of blood and urine, cranial magnetic resonance imaging (MRI), and whole exome sequencing (WES) of each patient was elaboratively analyzed.Result ID/DD patients with hemizygous variants in ATRX in China were characterized by moderate to profound ID/DD, facial malformations (microcephaly, hypertelorism, low nasal bridge and ear deformities), hypotonia and poor malmyelination. Five ARTX variants in six Chinese patients consisted of missense, in-frame deletion and frameshift variants, two of which were novel.Conclusion Six Chinese ID/DD patients were clinically and genetically diagnosed with ATRX mutations related syndrome (ATRX syndrome). And genotype–phenotype correlation was revealed in the participants, which expanded the clinical and genetic spectrum of ATRX syndrome.