title: Early noninvasive prenatal detection of a fetal CRB1 mutation causing Leber congenital amaurosis.
abstract: OBJECTIVE
  Leber congenital amaurosis (LCA) is one of the most severe inherited retinal dystrophies with the earliest age of onset. Mutations in the Crumbs homologue 1 (CRB1; OMIM 600105) gene explain 10%-24% of cases with LCA depending on the population. The aim of the present work was to study a fetal mutation associated to LCA in maternal plasma by a new methodology in the noninvasive prenatal diagnosis field: the denaturing High Performance Liquid Chromatography (dHPLC).
  
  
  METHODS
  This study presents the case of a compound heterozygous fetus for two mutations in CRB1 (1q3.1-q32.2). dHPLC and automated DNA sequencing were used to detect the paternally inherited fetal mutation in a maternal plasma sample collected at the 12th week of gestation. To test the detection limit of dHPLC, we made serial dilutions of paternal DNA in control DNA.
  
  
  RESULTS
  We were able to detect the presence of the paternally inherited fetal CRB1 mutation in maternal plasma by dHPLC. Moreover, by comparing chromatograms of serial dilutions to the plasma sample, we could ascertain that the percentage of fetal DNA in maternal plasma was at least 2%. However, the detection of the fetal mutation was not possible by automated DNA sequencing.
  
  
  CONCLUSIONS
  dHPLC seems to be sensitive enough to detect small amounts of fetal DNA in maternal plasma samples. It could be a useful tool for the noninvasive prenatal detection of paternally inherited point mutations associated with retinopathies.
authors.affiliation: Department of Genetics, Fundacion Jimenez Diaz-Capio, CIBERER, Madrid, Spain. abustamante@fjd.es
authors.forename: Ana
authors.initials: A
authors.lastname: Bustamante-Aragones
authors.forename: Elena
authors.initials: E
authors.lastname: Vallespin
authors.forename: Marta
authors.initials: M
authors.lastname: Rodriguez de Alba
authors.forename: Maria Jose
authors.initials: MJ
authors.lastname: Trujillo-Tiebas
authors.forename: Cristina
authors.initials: C
authors.lastname: Gonzalez-Gonzalez
authors.forename: Dan
authors.initials: D
authors.lastname: Diego-Alvarez
authors.forename: Rosa
authors.initials: R
authors.lastname: Riveiro-Alvarez
authors.forename: Isabel
authors.initials: I
authors.lastname: Lorda-Sanchez
authors.forename: Carmen
authors.initials: C
authors.lastname: Ayuso
authors.forename: Carmen
authors.initials: C
authors.lastname: Ramos
mesh_terms: D001766:Blindness / Q000151:congenital* / Q000235:genetics*; D002851:Chromatography, High Pressure Liquid; D004252:DNA Mutational Analysis; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D005333:Fetus / Q000378:metabolism; D005789:Genealogy and Heraldry; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009691:Nucleic Acid Denaturation; D015418:Optic Atrophies, Hereditary / Q000175:diagnosis* / Q000235:genetics*; D010375:Pedigree; D011247:Pregnancy; D011296:Prenatal Diagnosis
chemical_list: C448939:CRB1 protein, human; D005136:Eye Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins