kromosoomi esinemisest tingitud sündroom, a condition characterized by neonatal hepatitis, mental retardation, scaphocephaly, or other skull abnormality, micrognathia, blepharoptosis, low-set ears, corneal opacities, deafness, webbed neck, short digits, ventricular septal defects, Meckel's diverticulum, and other deformities, a congenital condition that is characterized especially by mental retardation and by craniofacial, cardiac, gastrointestinal, and genitourinary abnormalities, is caused by trisomy of the human chromosome numbered 18, and is typically fatal especially within the first year of life