Prenatal diagnosis
Suspicion of a chromosome abnormality is typically raised due to the presence of developmental delays. Diagnosis of proximal 18q is usually made via a routine chromosome analysis, although it may also be made by microarray analysis. Prenatal diagnosis is possible via amniocentesis or chorionic villus sampling. However, there have been multiple reports of missed prenatal diagnoses as the deletion can be difficult to identify on prenatal samples. In addition, small deletions within this region of the chromosome have been found in phenotypically normal individuals.