Table I.

The distribution of newborn screen results in the study population

Phenotype*	Study population (n)	Study population incidence (%) (95% CI)	Historical Prevalence** (%)
Sickle Cell Trait (+/− alpha-thalassemia)	287	10.3 (9.2–11.4)	12.8
FAS / AS	274	9.9
FASB	10	0.4
FASX	1	0.04
FBAS	1	0.04
ASF	1	0.04
Hemoglobin C trait	28	1.0 (0.6–1.4)	0.6
FAC / ACF	28	1.0
Sickle Cell Disease	33	1.2 (0.8–1.6)	3.0
FS§	28	1.0
FSA	2	0.07
FSB	2	0.07
FSX	1	0.04
Non-SCD Hemoglobinopathy§	6	0.2 (0–0.4)	0.6
FC§	3	0.1
F§	3	0.1	0.6
Normal Adult beta-globins	2418	87.1 (85.9–88.4)	82.3
FA / AF / A	2348	84.6
FAB	70	2.5
Indeterminate variant hemoglobin	4	0.1 (0–0.3)	0.7
FXA	1	0.04
FAX	3	0.1
Inadequate Samples without Retests	9
Total	2785	100

^*Indeterminate variant hemoglobins are denoted by ‘X’.

^**The historical values are taken from Simbeye, 1979 [8]. Hemoglobin Barts was not reported in that study.

^§These results may represent homozygous (e.g. hemoglobin C disease, beta thalassemia major, HPFH) or heterozygous disorders with a silent allele.