- Midtrimester diagnosis and anomalies in the dup(22q) syndrome: correlation of aneuploidy with low maternal serum alpha-fetoprotein and oligohydramnios. Johnson, M.P., Greb, A., Goyert, G., Drugan, A., Qureshi, F., Sacks, A.J., Evans, M.I. Am. J. Med. Genet. (1990)