Identification of a de novo variant in the ASXL2 gene related to Shashi-Pena syndrome

ASXL2 encodes proteins involved in epigenetic regulation and the assembly of transcription factors at specific genomic loci. Germline de novo truncating variants in ASXL2 have been implicated in Shashi-Pena syndrome, which results in features of developmental delay (DD), glabellar nevus flammeus, hypotonia, and cardiac disorders. However, the variants are rare, and the clinical spectrum may be incomplete. The clinical data such as brain MRI were collect. The whole exome sequencing was performed for genetic etiology analysis. Here, we report a patient with DD, hypotonia, early atrial septal defect, and abnormal white matter signal. She presented with Shashi-Pena syndrome with a truncated variant in ASXL2 (NM_018263.6, c.2142_2152del, p.Ser714Argfs*5). She died of a digestive tract infection when she was 1 year and 6 months old. Our study further expanded the spectrum of phenotypes and genetic variations of the syndrome, and we believe that it is necessary to screen the ASXL2 gene in patients with DD and cardiac and bone disorders.