Table 4.

HLA-A*03 in present and previous hemochromatosis cohorts ^a

Region (n)	A*03 positivity, %b	A*03 allele frequency c	Reference
Australia (129)d	39.5	0.2519	[13]
Alabama (43)d	58.1	0.3953	[14]
Italy (47)d	61.7	0.3936	[15]
Alabama (180)	78.3	0.4944	present study
Value of p	< 0.0001	< 0.0001

^a Abbreviation: HLA human leukocyte antigen

^b Positivity is defined as either A*03 homozygosity or heterozygosity. Positivity in the Australia cohort was lower than that in the previous Alabama (n = 43), Italy, and the present Alabama (n = 180) cohorts (p = 0.0098, 0.0015, and < 0.0001, respectively; post-hoc Fisher's exact tests). Positivity in the previous Alabama (n = 43) and Italy cohorts was lower than that in the present Alabama (n = 180) cohort (p = 0.0106 and 0.0239, respectively; post-hoc Fisher's exact tests)

^c Allele frequency is defined as the quotient of total A*03 alleles by total A alleles. A*03 allele frequency in the Australia cohort was lower than that in the previous Alabama (n = 43) and present Alabama (n = 180) cohorts (p = 0.0133 and < 0.0001, respectively; post-hoc Fisher's exact tests). A*03 allele frequency was lower in the Italy cohort than in the present Alabama cohort (p = 0.0147; post-hoc Fisher's exact test)

^d Patients in these cohorts were not characterized by HFE genotyping