Identification of haptoglobin alpha-2FF variants in mid-trimester maternal serum as potential markers for Down syndrome

Appl Theor Electrophor. 1990;1(5):233-41.


Exploratory protein analysis in mid-trimester maternal sera by 2-dimensional electrophoresis and image analysis was performed to determine the differences between mothers carrying fetuses with Down syndrome (DS) and control mothers. Nine haptoglobin alpha-1 and alpha-2 (Hp1 and Hp2) variants were detected. Three apparent isoforms of the Hp2FF protein having the same relative charge but different Mr's were detected, with the two smaller variants--Hp2FF (-0.7k) and Hp2FF (-1.3k)--believed to be first reported here. Ninety-two percent of the cases (n = 83) had the Hp2FF (-0.7k) protein, and 61% had Hp2FF (-1.3k). The geometric mean concentration of Hp2FF (Mr = 18.0 kd) was found to be significantly increased (P less than 0.01) in mid-trimester sera from cases (n = 27) compared to controls (n = 56). When the concentrations of the three Hp2FF isoforms were added, the cases had larger sums on average than controls (P less than 0.01).

MeSH terms

  • Age Factors
  • Down Syndrome / diagnosis*
  • Electrophoresis, Gel, Two-Dimensional
  • Female
  • Fetus
  • Genetic Markers
  • Genetic Variation
  • Haptoglobins / analysis*
  • Haptoglobins / genetics*
  • Humans
  • Molecular Weight
  • Pregnancy
  • Pregnancy Trimester, Second*


  • Genetic Markers
  • Haptoglobins