Causa inusual de cianosis en el recién nacido: hemoglobina M / Unusual cause of cyanosis in the newborn: hemoglobin M

Resumen La hemoglobina M es un desorden hereditario infrecuente, causante de metahemoglobinemia y, por ende, cianosis. Las manifestaciones clínicas de esta enfermedad son amplias y variadas, por lo que se debe considerar como diagnóstico diferencial en un recién nacido con cianosis sin otra causa aparente. A continuación, se presenta el caso de un recién nacido de 5 horas de vida con cianosis generalizada desde el nacimiento y con saturaciones de oxígeno de entre 60-70%, en el que se descartaron patologías como hipoxia perinatal, patología pulmonar o cardíaca y sepsis y se documentó un nivel de metahemoglobina elevado, reportado en 21,6%, con lo cual se estableció el diagnóstico de metahemoglobinemia. El tratamiento administrado fueron dos dosis de azul de metileno, pero no hubo respuesta clínica. Por este motivo, se realizó electroforesis de hemoglobina, la cual fue compatible con hemoglobina M (Iwate o Kankakee), lo que se confirma su causa congénita de metahemoglobinemia.

Abstract Hemoglobin M is a rare hereditary disorder that causes ethemoglobinemia and therefore cyanosis. The clinical manifestations of this condition differs considerably, so it should be considered as a differential diagnosis in a newborn with cyanosis, with no other apparent cause. The case of a 5 hours old newborn is presented below, with generalized cyanosis from birth with oxygen saturations between 60-70%, in whom, upon ruling out pathologies such as perinatal hypoxia, pulmonary disease, heart disease and sepsis, a high level of methemoglobin is documented, reported in 21,6%; the diagnosis of methemoglobinemia was established. The treatment administered was two doses of methylene blue with no response. For this reason, hemoglobin electrophoresis was performed, which was compatible with Hemoglobin M (Iwate or Kankakee), confirming its congenital cause.

Congenital Hypofibrinogenemia: Presentation of a Rare Coagulation Disorder.

Fibrinogen is a precursor of fibrin, which acts as a procoagulant plasma soluble protein. It is involved in blood viscosity and clot stability to help in the recovery of damaged blood vessels. We describe the case of a preterm newborn who presented with abdominal distension and manifestations of bleeding in venipuncture sites. In the initial laboratories, prolonged coagulation times were observed with a decreased concentration of fibrinogen. This newborn had transfusion support, with recovery in factor levels and a subsequent decrease in them. Based on this trend and ruling out other possible causes of hypofibrinogenemia, such as liver disease, sepsis, or disseminated intravascular coagulation, the diagnosis of congenital hypofibrinogenemia was made. This case report includes the diagnostic and therapeutic approach of an unusual hemorrhagic presentation in the newborn, highlighting the need for transfusion and dynamic fibrinogen replacement to prevent complications and seek rapid improvement in symptoms.

Herencia conjunta de α+-talasemia y portador de hemoglobina S / Co-inheritance of α+-thalassemia and sickle trait

Resumen En este reporte de caso se describe el primer paciente doble heterocigoto para alfa+-talasemia tipo -3,7 y rasgo heterocigoto por hemoglobina S en Costa Rica, diagnosticado desde su nacimiento por medio del tamizaje neonatal como heterocigoto para hemoglobina S. Luego de la detección de la hemoglobina S por tamizaje, el paciente fue referido al servicio de Hematología del Hospital Nacional de Niños para su seguimiento, en donde se observa hemograma con índices y morfología de glóbulos rojos sugestivos de alfa talasemia, con presentación de electroforesis de hemoglobina con patrón AS cuya expresión relativa de HbS era menor de lo esperado, lo que motivó a efectuar estudio molecular del gen de alfa globina, que confirmó el diagnóstico de alfa talasemia con deleción heterocigota de tipo -3,7 en herencia conjunta con la heterocigosis de hemoglobina S.

Abstract In this case report we describe the first patient compound heterozygous for type -3.7 alpha+ thalassemia and sickle cell trait in Costa Rica, who was diagnosed from birth by neonatal screening as heterozygous for hemoglobin S. After detection of hemoglobin S by screening, the patient was referred to the Hematology service of the National Children`s Hospital for follow-up, where hemogram with indexes and morphology of red blood cells suggestive of alpha thalassemia is observed, presenting hemoglobin electrophoresis with AS pattern whose relative expression of hemoglobin S was lower tan expected, which led to a molecular study of the alpha globin gene confirming the diagnosis of alpha thalassemia with heretozygous deletion of type -3.7, in co-inheritance with hemoglobin S heterozygosis.