Non-invasive detection of fetal genetic traits

Patent metadata

Field	Value
Publication number	US-9738931-B2
Application number	US-201313757637-A
Country	US
Kind code	B2
Filing date	Feb 1, 2013
Priority date	Oct 16, 2003
Publication date	Aug 22, 2017
Grant date	Aug 22, 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, comprising:
(a) extracting DNA comprising maternal and fetal DNA fragments from a substantially cell-free sample of blood plasma or blood serum of a pregnant human female;
(b) producing a fraction of the DNA extracted in (a) by:
(i) size discrimination of extracellular circulatory fetal and maternal DNA fragments, and
(ii) selectively removing the DNA fragments greater than approximately 300 base pairs,

wherein the DNA fraction after (b) comprises extracellular circulatory fetal and maternal DNA fragments of approximately 300 base pairs and less and a plurality of genetic loci of the extracellular circulatory fetal and maternal DNA fragments; and
(c) analyzing DNA fragments 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 step (b) comprises chromatography.

5. The method of claim 4 , wherein the chromatography comprises high performance liquid chromatography.

6. The method of claim 1 , wherein step (b) comprises electrophoresis.

7. The method of claim 6 , wherein the electrophoresis comprises capillary electrophoresis.

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

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

10. The method of claim 1 , wherein the size discrimination in (b) comprises nanotechnological means.

11. The method of claim 1 , wherein the analyzing comprises using nucleic acid arrays.

12. The method of claim 1 , wherein analyzing DNA fragments in the fraction of DNA produced in (b) is by a process comprising detection of a fetal chromosome aberration.

13. The method of claim 12 , wherein the fetal chromosome aberration is an aneuploidy.

14. The method of claim 12 , wherein the fetal chromosome aberration causes Down's syndrome.

Assignees

• 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

• C12Q1/6883 Primary

  for diseases caused by alterations of genetic material · CPC title

• C12Q2565/125

  Electrophoretic separation · CPC title