Our patient's phenotype, featuring a 3 × 4 cm parietal ACC without skull defect, severe bilateral lower limb hypoplasia (second and fifth toe nubs, absent nails), and a hemodynamically insignificant ASD, aligns closely with variants commonly associated with NOTCH1 mutations (emphasizing vascular/limb disruptions) or DOCK6 (recessive, multisystem involvement). This evidence concerns the gene NOTCH1 and atrial septal defect.