Expanded phenotypic and hematologic abnormalities beyond bone marrow failure in MECOM-associated syndromes.

The MECOM gene encodes multiple protein isoforms that are essential for hematopoietic stem cell self-renewal and maintenance. Germline MECOM variants have been associated with congenital thrombocytopenia, radioulnar synostosis and bone marrow failure; however, the phenotypic spectrum of MECOM-associated syndromes continues to expand and novel pathogenic variants continue to be identified. We describe eight unrelated patients who add to the previously known phenotypes and genetic defects of MECOM-associated syndromes. As each subject presented with unique MECOM variants, the series failed to demonstrate clear genotype-to-phenotype correlation but may suggest a role for additional modifiers that affect gene expression and subsequent phenotype. Recognition of the expanded hematologic and non-hematologic clinical features allows for rapid molecular diagnosis, early identification of life-threatening complications, and improved genetic counseling for families. A centralized international publicly accessible database to share annotated MECOM variants would advance their clinical interpretation and provide a foundation to perform functional MECOM studies.

Variation of Diagnostic Approaches and Treatment Practices for Hemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome Among Pediatric Subspecialists.

OBJECTIVE: To assess the diagnostic and treatment practices among a variety of subspecialists at pediatric institutions in the US. STUDY DESIGN: Using a web-based survey, we assessed the consultation, diagnostic, and treatment preferences of providers from the different pediatric subspecialties who care for pediatric patients with hemophagocytic lymphohistiocytosis (HLH)/macrophage activating syndrome (MAS). Domains included demographics, provider training level and specialty, experience and comfort level with the diagnosis and treatment of HLH/MAS, and institutional approaches toward the diagnosis and management of HLH/MAS. Participants also were given 2 case scenarios: one describing Epstein-Barr virus-associated HLH and another describing an underlying rheumatologic condition with MAS. RESULTS: Of 263 respondents, 23%, 29%, 39%, and 7% identified as hematology/oncology, rheumatology, general pediatrics/critical care/hospitalist, and allergy/immunology, respectively. For Epstein-Barr virus/HLH, hematology/oncology was the preferred first consultant by most respondents other than rheumatologists, of whom only 47% agreed. For MAS, 92% of respondents from all specialties favored a rheumatology consultation. Preferred diagnostic tests varied by subspecialty, with hematology/oncology more likely than rheumatology to order an infectious workup, natural killer cell function, soluble interleukin-2 receptor, bone marrow biopsy, and genetic testing. First-line therapy also varied, with hematology/oncology preferring dexamethasone and etoposide and rheumatology more often preferring methylprednisolone and anakinra. One-half of respondents were unaware of institutional algorithms for diagnosis and treatment of HLH/MAS. Most (85.6%) favored the development of treatment algorithms for HLH/MAS, and 90% supported a multidisciplinary approach. CONCLUSIONS: Current consulting patterns, diagnostic workup, and treatment approaches of HLH/MAS vary by specialty, highlighting the need for standardized management algorithms and institutional multidisciplinary HLH/MAS teams.

Lymphoma in Partial DiGeorge Syndrome: Report of 2 Cases.

Primary immunodeficiency diseases are associated with an increased tendency for noninfectious complications of autoimmunity and malignancy, particularly leukemia and lymphoma. The mechanisms of immune dysregulation have been linked to the combination of dysregulated immune cells and environmental factors such as infections. In particular, dysfunction in T-cell subsets and Epstein-Barr virus contributes to the development of autoimmunity and lymphoproliferative disease in primary immunodeficiency diseases. There are scant reports of patients with partial DiGeorge syndrome and Epstein-Barr virus-driven lymphoma. We report 1 patients with partial DiGeorge syndrome who developed lymphoma, and review reported cases in the literature.

Bone marrow necrosis in pediatric malignancies: 10-Year retrospective review and review of literature.

Bone marrow necrosis (BMN) is a rare pathologic finding, but when encountered is most often associated with malignancy. In adults, its presence correlates with an inferior prognosis, however in children the prognostic implication is unclear. We performed a retrospective review of 3,760 bone marrow specimens in patients ≤18 years over a 10-year period. BMN was identified in less than 1% of specimens and only in patients with leukemia, lymphoma, or neuroblastoma. BMN contributed to a delay in diagnosis; however, advanced medical imaging may serve as a tool to localize nonnecrotic areas for bone marrow sampling, facilitating an expedited diagnosis.

A Novel Variant in G6PD (c.1375C>G) Identified from a Hispanic Neonate with Extreme Hyperbilirubinemia and Low G6PD Enzymatic Activity.

We report a novel glucose-6-phosphate dehydrogenase (G6PD) variant (c.1375C>G) discovered in a 3-day-old Hispanic male child from Salt Lake City, UT, USA. This newborn presented with severe hyperbilirubinemia (29.8 mg/dL or 510 µmol/L) and marked hemolysis evidenced by elevated end-tidal carbon monoxide concentration (5.9 ppm, normal <1.7 ppm). Despite a very low prevalence of G6PD deficiency in Hispanic populations, we pursued testing for this condition and found he had low erythrocyte G6PD enzyme activity (2.8 U/g Hb, normal 9.9-16.6 U/g Hb) and a novel G6PD variant. His mother was heterozygous for this same variant, and she had a moderate decrease in G6PD enzyme activity (7.1 U/g Hb). On the basis of these findings, we propose this variant as a novel pathogenic mutation.

Dizygotic twins with prolonged jaundice and microcytic, hypochromic, hemolytic anemia with pyropoikilocytosis.

Dizygotic twin males, born at 34 weeks gestation, had prolonged jaundice, microcytic, hypochromic anemia, FABarts hemoglobin, elevated end-tidal CO, and blood films consistent with hereditary pyropoikilocytosis. DNA sequencing revealed both had a heterozygous alpha spectrin (SPTA1) mutation (c.460_462dup) inherited from their asymptomatic mother, plus a 3-base pair duplication in alpha globin (HBA2) (c.364_366dupGTG) inherited from their asymptomatic father.

Infantile Pyknocytosis: End-Tidal CO, %Micro-R Measurements, Next-Generation Sequencing, and Transfusion Avoidance with Darbepoetin.

Infantile pyknocytosis is a rare, self-limited, hemolytic condition of unknown pathogenesis. It is diagnosed when a neonate with Coombs-negative hemolytic anemia has abundant pyknocytes and a characteristic clinical course after other hemolytic disorders has been excluded. Previous reports suggest that transfusions might be avoidable in this condition by administering recombinant erythropoietin. We cared for a patient with this disorder where we employed novel diagnostics and therapeutics. Despite these, and a good outcome free of transfusions, we continue to consider the condition to be idiopathic.

Rare association of anophthalmia, complex congenital heart disease and pulmonary hypertension: case report. / Rara asociación de anoftalmía, malformación cardíaca compleja e hipertensión pulmonar: reporte de caso.

Clinical congenital anophthalmia is described as the uni- or bilateral absence of the eyeball that might occur in isolation or as part of a syndrome. It has a very low prevalence and its etiology is heterogeneous. Complex congenital cardiac malformations are also rare. The association of congenital anophthalmia and congenital heart disease is rarer still, and the etiology of those associations is not well understood yet. We report the case of a patient who had the very rare association of bilateral anophthalmia, multiple cardiac malformations and severe pulmonary hypertension.

La anoftalmía congénita clínica es la ausencia uni o bilateral del globo ocular, que se presenta de forma aislada o como parte de un síndrome. Tiene muy baja prevalencia y su etiología es heterogénea. La presencia conjunta de malformaciones cardíacas congénitas complejas también es poco frecuente. La asociación de anoftalmía congénita con cardiopatías congénitas es más rara aún, la etiología de tales asociaciones no es bien comprendida todavía. Se reporta el caso de una paciente que presentó la muy infrecuente asociación de anoftalmía bilateral, múltiples malformaciones cardíacas e hipertensión arterial pulmonar grave.