A 17-Month-old Boy With Pancytopenia Caused by a Rare Genetic Defect of Vitamin B12 Malabsorption.

Imerslund-Gräsbeck syndrome is an autosomal recessive disorder of vitamin B12 malabsorption presenting with megaloblastic anemia and mild proteinuria in childhood. The disorder is caused by biallelic pathogenic variants in the CUBN or AMN genes, which encode proteins involved in B12 absorption. We present the case of a 17-month-old boy with failure to thrive, pancytopenia, and fevers. His megaloblastic anemia was overlooked leading to unnecessary invasive testing. Findings on bone marrow biopsy prompted investigation for genetic disorders of B12 metabolism. Exome sequencing uncovered 1 known pathogenic variant and 1 novel likely pathogenic variant in CUBN, confirming the diagnosis of Imerslund-Gräsbeck syndrome.

Five days of fever and myocardial inflammation.

Multisystem inflammatory syndrome in children is an emerging pediatric illness associated with severe acute respiratory syndrome coronavirus 2 infection. The syndrome is rare, and evidence-based guidelines are lacking. This report reviews a patient who presented for medical care multiple times early in the course of his illness, thus offering near-daily documentation of symptoms and laboratory abnormalities. The patient did not have thrombocytopenia, anemia, or myocardial inflammation until the fifth day of fever. These laboratory abnormalities coincided with the onset of rash, conjunctival injection, vomiting, and diarrhea: clinical signs that could serve as indicators for when to obtain blood tests. The timing of this patient's onset of multisystem involvement suggests that testing for multisystem inflammatory syndrome in children after only 24 h of fever, as the Centers for Disease Control and Prevention recommends, may yield false-negative results. Testing for multisystem inflammatory syndrome in children after 4 days of fever may be more reliable.

Triple Diagnosis of Crohn's Disease, Celiac Disease, and Eosinophilic Esophagitis in a Child With Siderius-Hamel Syndrome.

Siderius-Hamel syndrome is a rare condition characterized by intellectual disability and distinct facial features. Crohn's disease-related eosinophilic esophagitis (EoE) has been reported; however, an association between celiac disease and EoE remains controversial. We present a case of a child with Siderius-Hamel syndrome who had characteristic findings of all these conditions-Crohn's disease, celiac disease, and EoE-an occurrence that to our knowledge has not been reported previously. The purpose of this report is to make physicians aware of this rare occurrence, so that it can be kept in mind while evaluating a patient with Siderius-Hamel syndrome presenting with gastrointestinal complaints.