Lethal hydrops fetalis due to congenital dyserythropoietic anemia in a newborn: association of a new skeletal abnormality

The congenital dyserythropoieitic anemias: genetics and pathophysiology

PURPOSE OF REVIEW

The congenital dyserythropoietic anemias (CDA) are hereditary disorders characterized by ineffective erythropoiesis. This review evaluates newly developed CDA disease models, the latest advances in understanding the pathogenesis of the CDAs, and recently identified CDA genes.

RECENT FINDINGS

Mice exhibiting features of CDAI were recently generated, demonstrating that Codanin-1 (encoded by Cdan1) is essential for primitive erythropoiesis. Additionally, Codanin-1 was found to physically interact with CDIN1, suggesting that mutations in CDAN1 and CDIN1 result in CDAI via a common mechanism. Recent advances in CDAII (which results from SEC23B mutations) have also been made. SEC23B was found to functionally overlap with its paralogous protein, SEC23A, likely explaining the absence of CDAII in SEC23B-deficient mice. In contrast, mice with erythroid-specific deletion of 3 or 4 of the Sec23 alleles exhibited features of CDAII. Increased SEC23A expression rescued the CDAII erythroid defect, suggesting a novel therapeutic strategy for the disease. Additional recent advances included the identification of new CDA genes, RACGAP1 and VPS4A, in CDAIII and a syndromic CDA type, respectively.

SUMMARY

Establishing cellular and animal models of CDA is expected to result in improved understanding of the pathogenesis of these disorders, which may ultimately lead to the development of new therapies.

Neonatal cholestasis and hepatosplenomegaly caused by congenital dyserythropoietic anemia type 1: A case report

BACKGROUND

Congenital dyserythropoietic anemia type 1 (CDA1) is an autosomal recessive disorder of ineffective erythropoiesis, resulting in increased iron storage. CDA1 is usually diagnosed in children and adolescents but can rarely present in the neonatal period with severe anemia at birth. There are no prior reports of neonatal liver histologic findings of CDA1. We report a case of CDA1 in a newborn presenting with severe anemia, cholestasis and liver failure, where liver biopsy helped confirm the diagnosis.

CASE SUMMARY

A term infant, born via emergency Cesarean section, presented with cholestasis, hepatosplenomegaly, multiorgan failure and severe anemia at birth. A prior pregnancy was significant for fetal demise at 35 wk without autopsy or known etiology for the fetal demise. Parents are both healthy and there is no history of consanguinity. On further evaluation, the patient was found to have severe ferritin elevation and pulmonary hypertension. An extensive infectious and metabolic work-up was negative. Salivary gland biopsy was negative for iron deposition. At 2 wk of age, a liver biopsy showed findings consistent with CDA1. A genome rapid sequencing panel revealed novel variants in the CDAN1 gene. The patient’s liver dysfunction, cholestasis and organomegaly resolved, however she remains transfusion-dependent.

CONCLUSION

We report liver pathology findings of CDA1 with a novel genetic mutation for the first time in a newborn.

Fibromuscular Dysplasia Complicated With Cerebral Stroke in a Child With Congenital Dyserythropoietic Anemia Type II

Congenital dyserythropoietic anemia type II belongs to a subtype of bone marrow failure syndrome, which is characterized by monolineage involvement and typical morphologic abnormalities in erythroid precursor cells resulting in different degrees of hyporegenerative anemia. Moreover, reticulocytosis, which is not corresponding to the degree of anemia, with jaundice and splenomegaly are major diagnostic criteria. Causative gene is located at SEC23B. Although stroke among children is rare, it can cause significant morbidity and mortality. Herein we present a 3-year-old male with congenital dyserythropoietic anemia type II who presented with stroke-like symptoms, and was diagnosed with fibromuscular dysplasia.

Nonimmune hydrops fetalis caused by G6PD deficiency hemolytic crisis and congenital dyserythropoietic anemia

We present a case of a female neonate who had a nonimmune hydrops fetalis and severe hemolytic anemia due to a rare combination of glucose-6-phosphate dehydrogenase (G6PD) deficiency and congenital dyserythropoietic anemia. We conclude that in severe cases with persistent anemia one should search after delivery for a second reason other than G6PD deficiency alone.

CDAII presenting as hydrops foetalis: molecular characterization of two cases

We report two patients with very severe congenital dyserythropoietic anemia presenting with hydrops foetalis, previously classified as "atypical" CDAs since they presented CDAII-like erythroblastic morphological features lacking other diagnostic CDAII markers. Molecular characterization of SEC23B gene, recently described as responsible of CDAII, revealed the presence of Glu109Lys/Arg701Cys and Glu109Lys/Cys66Tyr mutations, respectively. This finding leads to a re-classification of these cases and underlines phenotypic heterogeneity of CDAII, demonstrating for the first time that CDAII may be associated with hydrops foetalis and intrauterine death.

Advances in the understanding of the congenital dyserythropoietic anaemias

The congenital dyserythropoietic anaemias (CDAs) are a heterogeneous group of diseases in which the anaemia is predominantly caused by dyserythropoiesis and marked ineffective erythropoiesis; three major (types I, II and III) and several minor subgroups have been identified. Additional information on the natural history of these conditions, the beneficial role of splenectomy in CDA type II and efficacy of interferon-alpha in type I have recently been reported. A disease gene has been localised to a chromosomal segment in the three major types and in CDA type I, a disease gene has been identified (CDANI). Mutations have been detected in both familial and sporadic cases but the predicted protein structure gives few clues as to its function. In both type I and II, there are cases unlinked to the identified localisations, suggesting genetic heterogeneity.