We received a question about MCH and MCV. The question concerned an individual with Down syndrome who had a high MCH and MCV.
MCH is mean corpuscular hemoglobin (the average amount of hemoglobin in the red blood cells). MCV is mean corpuscular volume (the average size of the red blood cells. In people with Down syndrome, MCH and MCV are often elevated and this may have to do with the way people with DS metabolize folic acid or perhaps more rapid turn-over of red blood cells.
If the individual in the question had a low MCH and MCV: Low MCH and MCV are associated with iron deficiency anemia, anemia of chronic illnesses, and thalassemia. In people with Down syndrome, one must consider celiac disease as a possible cause of iron deficiency anemia.
Further work-up by your practitioner is warranted when a low MCH and/or MCV is found. With a normal hemoglobin and hematocrit (blood count), an elevated MCH and MCV are generally considered normal variants in people with DS.
For more resources, please see the Hematology section of our Resource Library.