A high-throughput population screening system for the estimation of genetic risk for type 1 diabetes: an application for the TEDDY (the Environmental Determinants of Diabetes in the Young) study.
BACKGROUND
In the TEDDY (The Environmental Determinants of Diabetes in the Young) study patient eligibility is based on the presence of some selected type 1 diabetes risk-associated human leukocyte antigen DR-DQ genotypes. A practical screening strategy was needed with efficient exclusion of ineligible patients at an early stage. Also, a simple, low-cost, and fast screening system was essential for the primary step of the risk assessment including thousands of samples.


METHODS
A homogeneous genotyping system utilizing an asymmetric polymerase chain reaction (PCR) and subsequent hybridization of allele-specific probes was designed to be used as the first screening step. This assay was combined with methods further elucidating the genetic risk of type 1 diabetes to screen for high-risk individuals.


RESULTS
The homogeneous assay platform allows the typing of hundreds of samples within one working day. The costs of the assay are minimal, and the reduction in hands-on time provides considerable improvements compared to the heterogeneous genotyping methods comprising separate PCR and hybridization steps. The primary selection criteria used in the first step proved to be efficient since the numbers of samples typed in subsequent stages were markedly reduced.


CONCLUSIONS
The presented assay system provides a practical approach to the rapid screening of thousands of samples at low cost, a general starting point for large-scale screening studies.
Kiviniemi
Minna
M
Immunogenetics Laboratory and MediCity Research Laboratory, University of Turku, Finland. minna.kiviniemi@utu.fi
Hermann
Robert
R
Nurmi
Jussi
J
Ziegler
Anette G
AG
Knip
Mikael
M
Simell
Olli
O
Veijola
Riitta
R
Lövgren
Timo
T
Ilonen
Jorma
J
D000293:Adolescent; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology* / Q000235:genetics*; D004777:Environment; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006680:HLA Antigens / Q000235:genetics; D006681:HLA-D Antigens / Q000235:genetics; D006683:HLA-DQ Antigens / Q000235:genetics; D059866:HLA-DQ beta-Chains; D006801:Humans; D008403:Mass Screening / Q000379:methods; D016133:Polymerase Chain Reaction; D012307:Risk Factors
D006680:HLA Antigens; D006681:HLA-D Antigens; D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen