TY - GEN T1 - Assay used in serum screening for Down's syndrome may depend on ethnic make up of population JO - BRIT MED J PY - 1996/08/03 AU - Gilbert L AU - Nicholl J AU - Mander A ED - VL - 313 IS - 7052 SP - 297 EP - 297 Y2 - 2024/12/22 ER -