Immunohistochemistry revealed 70.48 ± 49.59 AIRE-positive cells/mm(2) in DS versus 154.70 ± 61.16 AIRE-positive cells/mm(2) in controls (p < 0.0001), and quantitative PCR as well as DNA microarray data confirmed those results.
Since this disease is caused by mutations in the gene AIRE on chromosome 21, one might speculate that altered expression of AIRE contributes to autoimmune disease in Down syndrome.
Finally, the association of alopecia areata with Down's syndrome, the high frequency of alopecia areata in autoimmune polyglandular syndrome type I due to mutations of the autoimmune regulator (AIRE) gene on chromosome 21q22.3 and the finding of association with MX1, another gene in the Down's syndrome region of chromosome 21 indicate this area of the genome as a promising target for future-family based investigations.
To examine the age of onset of insulin dependent diabetes mellitus (IDDM) in children with Down's syndrome compared with non-trisomic individuals, and to assess whether differences might be related to disomic homozygosity at the autoimmune polyglandular disease type 1 (APECED) gene locus.