Congenital Dyserythropoietic Anemia Type I (CDAI)

Inheritance: autosomal recessive

Clinical and laboratory features:

(1) macrocytic anemia with MCV > 90 fL

(2) ineffective erythropoiesis with reticulocytopenia relative to the degree of anemia

(3) iron overload

(4) splenomegaly secondary to ineffective erythropoiesis

(5) distal limb dimorphism (hypoplastic nails, syndactyly, duplicate fourth metatarsal)

(6) hydrops fetalis at birth

Additional clinical findings may include:

(1) osteoporosis

(2) cholelithiasis

(3) pulmonary arterial hypertension

(4) hypothyroidism

(5) diabetes mellitus

Findings on peripheral blood smear:

(1) macrocytosis

(2) elliptocytes

(3) basophilic stippling

(4) nucleated RBCs