COL18A1 and Down syndrome: In our sample, we also associated one case each of Noonan syndrome (causative variant in the BRAF gene), Knobloch syndrome (causative variants in the COL18A1 gene), Marfan syndrome (causative variant in the FBN1 gene), MEB disease (causative variants in the POMGNT1 gene), CHARGE syndrome (causative variant in the CHD7 gene), Down syndrome (trisomy 21), Prader-Willi syndrome (microdeletion of the 15q11.2 region), and 8q13 microdeletion syndrome.