Non-invasive detection of fetal genetic traits

Patent metadata

Field	Value
Publication number	US-9580751-B2
Application number	US-201113029995-A
Country	US
Kind code	B2
Filing date	Feb 17, 2011
Priority date	Oct 16, 2003
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

Blood plasma of pregnant women contains fetal and (generally >90%) maternal circulatory extracellular DNA. Most of said fetal DNA contains ≦500 base pairs, said maternal DNA having a greater size. Separation of circulatory extracellular DNA of <500 base pairs results in separation of fetal from maternal DNA. A fraction of a blood plasma or serum sample of a pregnant woman containing, due to size separation (e.g. by chromatography, density gradient centrifugation or nanotechnological methods), extracellular DNA substantially comprising ≦500 base pairs is useful for non-invasive detection of fetal genetic traits (including the fetal RhD gene in pregnancies at risk for HDN; fetal Y chromosome-specific sequences in pregnancies at risk for X chromosome-linked disorders; chromosomal aberrations; hereditary Mendelian genetic disorders and corresponding genetic markers; and traits decisive for paternity determination) by e.g. PCR, ligand chain reaction or probe hybridization techniques, or nucleic acid arrays.

First claim

What is claimed is:

1. A method for preparing a deoxyribonucleic acid (DNA) fraction from a pregnant human female useful for analyzing a genetic locus involved in a fetal chromosomal aberration, comprising:
(a) extracting DNA from a substantially cell-free sample of blood plasma or blood serum of a pregnant human female to obtain extracellular circulatory fetal and maternal DNA fragments;
(b) producing a fraction of the DNA extracted in (a) by:
(i) size discrimination of extracellular circulatory DNA fragments, and
(ii) selectively removing the DNA fragments greater than approximately 500 base pairs,

wherein the DNA fraction after (b) comprises a plurality of genetic loci of the extracellular circulatory fetal and maternal DNA; and
(c) analyzing a genetic locus in the fraction of DNA produced in (b).

2. The method of claim 1 , wherein the DNA extracted in (a) is from a substantially cell-free sample of blood plasma.

3. The method of claim 1 , wherein the DNA extracted in (a) is from a substantially cell-free sample of blood serum.

4. The method of claim 1 , wherein the analyzing a genetic locus comprises amplifying DNA.

5. The method of claim 4 , wherein the amplifying comprises use of a polymerase chain reaction.

6. The method of claim 4 , wherein the amplifying comprises use of a ligase chain reaction.

7. The method of claim 1 , wherein the size discrimination in (b) comprises centrifugation.

8. The method of claim 7 , wherein the centrifugation includes density gradient centrifugation.

9. The method of claim 1 , wherein the fetal chromosomal aberration is an aneuploidy.

10. The method of claim 1 , wherein the fetal chromosomal aberration causes Down's Syndrome.

Assignees

• Hahn Sinuhe
• Holzgreve Wolfgang
• Zimmermann Bernhard
• Li Ying
• Sequenom Inc

Inventors

• Hahn Sinuhe
• Holzgreve Wolfgang
• Zimmermann Bernhard
• Li Ying

Classifications

• C12Q1/6806 Primary

  Preparing nucleic acids for analysis, e.g. for polymerase chain reaction [PCR] assay (C12Q1/6804 takes precedence) · CPC title

• C12Q2600/156

  Polymorphic or mutational markers · CPC title

• C12Q2565/125

  Electrophoretic separation · CPC title

• C12Q1/6883 Primary

  for diseases caused by alterations of genetic material · CPC title