CDIN1 gene

Variants (also called mutations) in the CDIN1 gene have been identified in people with congenital dyserythropoietic anemia (CDA) type I. This condition is characterized by a shortage of red blood cells that is caused by abnormal red blood cell formation (dyserythropoietic anemia). In people with CDA type I, immature red blood cells cannot develop into functional, mature cells. As a result, the number of mature and functioning red blood cells decreases, which leads to weakness, yellowing of the skin and eyes (jaundice), an enlarged liver and spleen (hepatosplenomegaly), the buildup of too much iron (iron overload), and skeletal problems in people with CDA type I.

Most CDIN1 gene variants change single protein building blocks (amino acids) in the CDAN1-interacting nuclease 1 protein. The CDIN1 gene variants that cause CDA type I likely reduce the function of CDAN1-interacting nuclease 1 rather than completely eliminate it, since the protein appears to be essential for life. It is unclear how CDIN1 gene variants cause the characteristic features of CDA type I. A shortage of functional protein somehow disrupts the normal development of red blood cells. In people with CDA type I, immature red blood cells called erythroblasts are large and may have more than one nucleus. These abnormal erythroblasts cannot develop into functional, mature red blood cells. The resulting shortage of healthy red blood cells leads to the characteristic signs and symptoms of anemia and the other features of CDA type I.