Table 1.

Comparison of patients’ hematologic and iron metabolism characteristics and derivative hepcidin and ferritin indices

	No.	Mean	Minimum	Maximum	Median	SD	SEM	Wilcoxon signed rank test 2-tailed P
								vs mut/mut	vs cID	vs +/+
Age (y)
mut/mut	43*	13	1	50	10	12	2
cID	57	23	1	69	16	21	3	.0006
+/+	31	38	2	90	41	22	4	<.0001	.2886
mut/+	64	37	3	73	39	18	2	<.0001	<.0001	.5574
Hemoglobin (g/dL)
mut/mut	43*	9.0	5.7	11.7	8.8	1.3	0.2
cID	59	9.8	3.6	13.3	10.1	2.1	0.3	.0005
+/+	35	14.1	12.2	15.9	14.0	1.1	0.2	<.0001	<.0001
mut/+	65	13.5	8.7	16.5	13.6	1.5	0.2	<.0001	<.0001	.018
Mean red blood cell volume (fL)
mut/mut	43*	61.2	50.0	75.1	60.0	6.3	1.0
cID	59	72.3	55.6	96.2	72.1	8.9	1.2	<.0001
+/+	35	90.1	77.1	99.7	90.1	5.1	0.9	<.0001	<.0001
mut/+	65	86.1	68.1	107.3	86.2	6.7	0.8	<.0001	<.0001	<.0001
Iron (μg/dL)
mut/mut	44	19	11	44	17	7	1
cID	59	30	12	72	26	14	2	<.0001
+/+	35	86	35	126	87	27	5	<.0001	<.0001
mut/+	66	74	15	176	70	35	4	<.0001	<.0001	.0017
Total iron binding capacity (μg/dL)
mut/mut	44	365	182	503	359	67	10
cID	59	433	186	626	442	98	13	<.0001
+/+	35	404	311	564	392	74	12	.0028	.0046
mut/+	66	386	179	556	387	69	9	.0007	<.0001	.3558
Transferrin saturation (%)
mut/mut	44	5	3	13	5	3	0
cID	59	7	2	15	7	4	0	<.0001
+/+	35	23	8	41	21	9	2	<.0001	<.0001
mut/+	66	20	3	56	20	11	1	<.0001	<.0001	.2729
Ferritin (ng/mL)
mut/mut	44	96.9	2.8	511.4	66.2	100.2	15.1
cID	59	51.9	1.3	636.0	10.2	106.5	13.9	.0004
+/+	35	78.3	5.9	302.0	43.3	78.1	13.2	.7524	<.0001
mut/+	66	115.8	2.7	536.4	70.9	117.3	14.4	.0183	<.0001	<.0001
Zinc protoporphyrin:heme ratio (μmol/mol)
mut/mut	24	120	474	253	249	99	20
cID	45	33	605	206	180	136	20	.0069
+/+	34	24	103	46	43	15	3	<.0001	<.0001
mut/+	61	21	344	62	46	53	7	<.0001	<.0001	.0081
Serum transferrin receptor (mg/L)
mut/mut	19	14.53	5.18	28.82	15.19	5.23	1.2
cID	28	15.26	3.45	62.56	9.52	14.14	2.67	.33
+/+	23	3.75	2.3	8.45	3.23	1.49	0.31	<.0001	<.0001
mut/+	51	4.11	1.89	14.77	3.63	2.17	0.30	<.0001	<.0001	.0066
C-reactive protein (mg/L)
mut/mut	42	0.15	0.03	2.06	0.09	0.34	0.05
cID	58	0.35	0.03	4.20	0.10	0.73	0.10	.0046
+/+	35	0.31	0.03	2.32	0.10	0.54	0.09	.003	.0069
mut/+	63	0.37	0.03	4.10	0.10	0.8	0.10	.0005	.0015	.0015
Hepcidin (ng/mL)
mut/mut	44	69.7	8.8	219.3	62.8	45.5	6.9
cID	59	21.5	2.8	105.1	7.0	27.7	3.6	<.0001
+/+	35	20.8	4.1	76.9	14.8	17.3	2.9	<.0001	<.0001
mut/+	66	28.5	2.9	91.8	23.6	18.8	2.3	<.0001	<.0001	<.0001
Iron/log(ferritin)
mut/mut	44	11.3	6.5	31.3	9.2	5.7	0.9
cID	59	31.2	6.4	122.9	28.5	18.9	2.5	<.0001
+/+	35	53.8	19.9	99.9	51.6	18.4	3.1	<.0001	<.0001
mut/+	66	40.9	12.1	103.0	39.0	19.0	2.3	<.0001	<.0001	<.0001
Transferrin saturation/log(ferritin)
mut/mut	44	3.2	1.7	8.8	2.7	1.7	0.3
cID	59	7.1	2.0	23.9	6.5	3.5	0.5	<.0001
+/+	35	13.6	4.6	26.9	13.2	4.9	0.8	<.0001	<.0001
mut/+	66	11.0	3.0	32.8	11.0	5.6	0.7	<.0001	<.0001	.0004
Hepcidin/ferritin
mut/mut	44	1.3	0.1	6.8	1.0	1.3	0.2
cID	59	1.2	0.1	10.8	0.8	1.6	0.2	.4183
+/+	35	0.4	0.1	1.4	0.3	0.3	0	<.0001	<.0001
mut/+	66	0.5	0.0	2.6	0.3	0.5	0.1	<.0001	<.0001	.0533
Iron/log(hepcidin)
mut/mut	44	11.1	5.3	30.2	9.7	5.2	0.8
cID	59	32.1	7.0	80.9	27.2	17.8	2.3	<.0001
+/+	35	77.1	26.6	169	69.7	29.8	5.0	<.0001	<.0001
mut/+	66	57.7	9.4	170.8	49.9	32.0	3.9	<.0001	<.0001	.0003
Transferrin saturation/log(hepcidin)
mut/mut	44	3.2	1.4	8.9	2.5	1.8	0.3
cID	59	7.5	2.1	19.2	6.2	4.0	0.5	<.0001
+/+	35	19.6	6.2	40.2	18.1	8.0	1.3	<.0001	<.0001
mut/+	66	15.8	2.3	48.8	13.9	9.9	1.2	<.0001	<.0001	.0058

+/+, wild-type controls; cID, no TMPRSS6 mutations detected; mut/+, clinically unaffected TMPRSS6 heterozygotes; mut/mut, biallelic TMPRSS6 mutations detected; SD, standard deviation; SEM, standard error of the mean.

^*A concurrent complete blood count was not available for 1 patient.