Identification of novel FOXP1 variants in four unrelated patients with intellectual disability and speech impairment

BackgroundTo document the clinical phenotypes and identify the genetic causes of four unrelated children with intellectual disability and speech impairment.MethodsTrio-based whole exome sequencing (Trios) was performed for four probands and their parents. Identified variants underwent pathogenicity assessment utilizing in silico protein structure prediction and RNA analysis.ResultsTrios revealed four novel de novo heterozygous FOXP1 variants: a frameshift variant c.1909dup (p.Glu637Glyfs*10), tw