title: Fragile X protein in newborn dried blood spots.
abstract: BACKGROUND
  The fragile X syndrome (FXS) results from mutation of the FMR1 gene that prevents expression of its gene product, FMRP. We previously characterized 215 dried blood spots (DBS) representing different FMR1 genotypes and ages with a Luminex-based immunoassay (qFMRP). We found variable FMRP levels in the normal samples and identified affected males by the drastic reduction of FMRP.
  
  
  METHODS
  Here, to establish the variability of expression of FMRP in a larger random population we quantified FMRP in 2,000 anonymous fresh newborn DBS. We also evaluated the effect of long term storage on qFMRP by retrospectively assaying 74 aged newborn DBS that had been stored for 7-84 months that included normal and full mutation individuals. These analyses were performed on 3 mm DBS disks. To identify the alleles associated with the lowest FMRP levels in the fresh DBS, we analyzed the DNA in the samples that were more than two standard deviations below the mean.
  
  
  RESULTS
  Analysis of the fresh newborn DBS revealed a broad distribution of FMRP with a mean approximately 7-fold higher than that we previously reported for fresh DBS in normal adults and no samples whose FMRP level indicated FXS. DNA analysis of the lowest FMRP DBS showed that this was the low extreme of the normal range and included a female carrying a 165 CGG repeat premutation. In the retrospective study of aged newborn DBS, the FMRP mean of the normal samples was less than 30% of the mean of the fresh DBS. Despite the degraded signal from these aged DBS, qFMRP identified the FXS individuals.
  
  
  CONCLUSIONS
  The assay showed that newborn DBS contain high levels of FMRP that will allow identification of males and potentially females, affected by FXS. The assay is also an effective screening tool for aged DBS stored for up to four years.
authors.affiliation: Department of Developmental Biochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York, 10314, USA. tatyana.adayev@opwdd.ny.gov.
authors.forename: Tatyana
authors.initials: T
authors.lastname: Adayev
authors.affiliation: Department of Developmental Biochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York, 10314, USA. giuseppe.x.lafauci@opwdd.ny.gov.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: LaFauci
authors.affiliation: Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York, 10314, USA. carl.dobkin@opwdd.ny.gov.
authors.forename: Carl
authors.initials: C
authors.lastname: Dobkin
authors.affiliation: Wadsworth Center, New York State Department of Health, Albany, New York, USA. mx08@health.state.ny.us.
authors.forename: Michele
authors.initials: M
authors.lastname: Caggana
authors.affiliation: NSW Newborn Screening Programme & University of Sydney, Sydney, Australia. veronica.wiley@health.nsw.gov.au.
authors.forename: Veronica
authors.initials: V
authors.lastname: Wiley
authors.affiliation: The NSW GOLD Service, Hunter Genetics, Newcastle, Australia. geneticfield@gmail.com.
authors.forename: Michael
authors.initials: M
authors.lastname: Field
authors.affiliation: NSW Newborn Screening Programme & University of Sydney, Sydney, Australia. tiffany.wotton@health.nsw.gov.au.
authors.forename: Tiffany
authors.initials: T
authors.lastname: Wotton
authors.affiliation: Department of Developmental Biochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York, 10314, USA. richard.kascsak@opwdd.ny.gov.
authors.forename: Richard
authors.initials: R
authors.lastname: Kascsak
authors.affiliation: Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York, 10314, USA. sally.nolin@opwdd.ny.gov.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Nolin
authors.affiliation: Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York, 10314, USA. anne.glicksman@opwdd.ny.gov.
authors.forename: Anne
authors.initials: A
authors.lastname: Glicksman
authors.affiliation: Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York, 10314, USA. nicole.d.ersalesi@opwdd.ny.gov.
authors.forename: Nicole
authors.initials: N
authors.lastname: Hosmer
authors.affiliation: Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York, 10314, USA. ted.brown@opwdd.ny.gov.
authors.forename: W Ted
authors.initials: WT
authors.lastname: Brown
mesh_terms: D001793:Blood Preservation; D059788:Dried Blood Spot Testing / Q000379:methods*; D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000097:blood* / Q000235:genetics; D005600:Fragile X Syndrome / Q000097:blood* / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1; C497683:FMR1 protein, human