HFE C282Y Homozygotes (hfe + c282y_homozygote)

Distribution by Scientific Domains


Selected Abstracts


Relationships of serum free thyroxine and erythrocyte measures in euthyroid HFE C282Y homozygotes and control subjects: the HEIRS Study

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 3 2010
J. C. BARTON
Summary Hemoglobin (Hb) levels and mean corpuscular volume (MCV) are abnormal in some persons with hemochromatosis or thyroid disorders. We sought to determine whether serum free thyroxine (T4) affects erythrocyte measures in euthyroid adults with or without C282Y homozygosity. We evaluated 488 white HFE C282Y homozygotes and controls (no HFE C282Y or H63D; normal serum iron measures) identified in screening; we excluded those with thyroid disorders, anemia, erythrocytosis, or serum ferritin (SF) <34 pmol/l. In the remaining 141 C282Y homozygotes and 243 controls, we evaluated correlations of log10 free T4 with Hb, RBC, MCV, and red blood cell distribution width (RDW). C282Y homozygotes had lower mean age, higher mean Hb, MCV, and log10 SF, and lower mean RBC and RDW than controls; mean log10 free T4 did not differ significantly. In HFE C282Y homozygotes, there was no significant correlation of log10 T4 with erythrocyte measures. In controls, there was a positive correlation of log10 T4 with Hb (P = 0.0096) and a negative correlation with RDW (P = 0.0286). Among euthyroid white adults without iron deficiency, there are significant correlations of log10 free T4 with Hb and RDW in controls, but not in HFE C282Y homozygotes. [source]


Heritability of serum iron measures in the hemochromatosis and iron overload screening (HEIRS) family study

AMERICAN JOURNAL OF HEMATOLOGY, Issue 2 2010
Christine E. McLaren
Heritability is the proportion of observed variation in a trait among individuals in a population that is attributable to hereditary factors. The Hemochromatosis and Iron Overload Screening family study estimated heritability of serum iron measures. Probands were HFE C282Y homozygotes or non-C282Y homozygotes with elevated transferrin saturation (TS > 50%, men; TS > 45%, women) and serum ferritin concentration (SF > 300 ,g/L, men; SF > 200 ,g/L, women). Heritability (h2) was estimated by variance component analysis of TS, natural logarithm (ln) of SF, and unsaturated iron-binding capacity (UIBC). Participants (N = 942) were 77% Caucasians, 10% Asians, 8% Hispanics, and 5% other race/ethnicities. Average age (SD) was 49 (16) years; 57% were female. For HFE C282Y homozygote probands and their family members, excluding variation due to HFE C282Y and H63D genotype and measured demographic and environmental factors, the residual h2 (SE) was 0.21 (0.07) for TS, 0.37 (0.08) for ln SF, and 0.34 (0.08) for UIBC (all P < 0.0004 for comparisons with zero). For the non-C282Y homozygote proband group, residual h2 was significant with a value of 0.64 (0.26) for ln SF (P = 0.0096). In conclusion, serum iron measures have significant heritability components, after excluding known genetic and nongenetic sources of variation. Am. J. Hematol. 85:101,105, 2010. © 2009 Wiley-Liss, Inc. [source]