Development of genomic reference materials for Huntington disease genetic testing.
OBJECTIVE
Diagnostic and predictive testing for Huntington disease requires an accurate measurement of CAG repeats in the HD (IT15) gene. However, precise repeat sizing can be technically challenging, and is complicated by the lack of quality control and reference materials (RM). The aim of this study was to characterize genomic DNA from 14 Huntington cell lines available from the National Institute of General Medical Sciences Human Genetic Cell Repository at the Coriell Cell Repositories for use as reference materials for CAG repeat sizing.


METHODS
Fourteen Huntington cell lines were selected for study. The alleles in these materials represent a large range of sizes that include important diagnostic cutoffs and allele combinations. The allele measurement study was conducted by ten volunteer laboratories using a variety of polymerase chain reaction-based in-house developed methods and by DNA sequence analysis.


RESULTS
The Huntington alleles in the 14 genomic DNA samples range in size from 15 to 100 CAG repeats. There was good agreement among the ten laboratories, and thus, the 95% confidence interval was small for each measurement. The allele size determined by DNA sequence analysis agreed with the laboratory developed tests.


CONCLUSIONS
These DNA materials, which are available from Coriell Cell Repositories, will facilitate accurate and reliable Huntington genetic testing.
Kalman
Lisa
L
Laboratory Practice Evaluation and Genomics Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. LKalman@cdc.gov
Johnson
Monique A
MA
Beck
Jeanne
J
Berry-Kravis
Elizabeth
E
Buller
Arlene
A
Casey
Brett
B
Feldman
Gerald L
GL
Handsfield
James
J
Jakupciak
John P
JP
Maragh
Samantha
S
Matteson
Karla
K
Muralidharan
Kasinathan
K
Richie
Kristy L
KL
Rohlfs
Elizabeth M
EM
Schaefer
Frederick
F
Sellers
Tina
T
Spector
Elaine
E
Richards
C Sue
CS
D002460:Cell Line; D005820:Genetic Testing / Q000592:standards*; D015894:Genome, Human; D006801:Humans; D000071058:Huntingtin Protein; D006816:Huntington Disease / Q000175:diagnosis*; D009419:Nerve Tissue Proteins / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics; D012015:Reference Standards; D012091:Repetitive Sequences, Nucleic Acid
C086055:HTT protein, human; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins