The small supernumerary marker chromosome (sSMC) in<unk>  usually arises spontaneously. It may be hereditary and parents may be mosaic for the marker chromosome, but show no phenotypic symptoms of the syndrome. This sSMC may be small, large, or ring-shaped, and typically includes 2 Mb, i.e. 2 million DNA base pairs, termed the<unk>  critical region, located on its q arm(s) between its band 11 and terminus (area notated as 22pter→q11)(also see small supernumerary marker chromosomes in<unk> . This area contains the CECR1, SLC25A18, and ATP6V1E1 genes which are strong candidate genes for causing or promoting at least some of the birth defects in<unk> .
Cat eye syndrome
Ocular ischemic syndrome
Toxic amblyopia
Motion-induced blindness
Phacolytic glaucoma
Dry eye syndrome
Computer vision syndrome
Phantom eye syndrome