Estimation of genetic risk for Type 1 diabetes mellitus in newborns on dried blood spot.
BACKGROUND
The main contribution to genetic susceptibility for Type 1 Diabetes Mellitus (T1DM) is conferred by the Human Leukocyte Antigens (HLA).


OBJECTIVE
We evaluated the feasibility of large scale screening on Dried Blood Spot (DBS) to estimate the genetic risk for T1DM in newborns.


METHODS
Peripheral blood DBS samples from 256 newborns, were genotyped for HLA DRB1 and DQB1 alleles identification by a commercially available assay based on a dissociation enhancer lanthanide fluorescence system available in many newborn screening laboratories. Results were compared with those obtained in two wide multicentric studies on cord blood (DIABFIN and PREVEFIN).


RESULTS
Genotyping on DBS revealed 6 subjects at high risk for T1DM, 99 at moderate risk for T1DM and the remaining at low risk for T1DM. We found 100% concordance between both techniques for HLA-DQB1 and DRB1 determination, confirming the feasibility of large scale screening on DBS.


CONCLUSIONS
DBSs represent a resource for future studies about new genetics markers. This assay for estimate the genetic risk of T1DM on DBS showed an excellent sensitivity, specificity and accuracy compared with conventional techniques. Moreover, this assay resulted less expensive, and it could be easily performed on material already collected for newborn screening programs.
Giannattasio
A
A
Department of Pediatrics, University of Genova, IRCCS Giannina Gaslini Institute, Genova, Italy.
Caruso
U
U
Napoli
F
F
Salina
A
A
Aloi
C
C
Lorini
R
R
d'Annunzio
G
G
D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006683:HLA-DQ Antigens / Q000032:analysis*; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000032:analysis*; D059811:HLA-DRB1 Chains; D006801:Humans; D007231:Infant, Newborn / Q000097:blood* / Q000276:immunology; D015997:Neonatal Screening / Q000379:methods*; D012680:Sensitivity and Specificity
D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains