Abstract:Cyanosis in an apparently healthy newborn baby may be caused by hemoglobin variants associated with the formation of methemoglobin, collectively known as M hemoglobins. They should not be confused with genetic alterations in methemoglobin reductase enzyme systems of red cells since treatment and prognosis are completely different. A newborn male child was noted to be significantly cyanotic at birth and is the basis for this report. Hemoglobin isoelectric focusing, acid and alkaline gel electrophoresis, and HBA… Show more
“…Since chemical characterizations of Hb M were first reported in the late 1950s and early 1960s by Gerald [6, 7], the rare globin chain variants have been investigated by chromatography, electrophoresis, and gene sequencing [1, 2, 5].…”
Section: Discussionmentioning
confidence: 99%
“…Hb M caused by a mutation in α-, β-, or γ-globin can lead to spontaneous oxidation of the ferrous ion in the heme and cannot transport or release oxygen in tissues. Hb M disease causes cyanosis that is unresponsive to oxygen therapy [1, 2]. Some variants might need to be considered in the differential diagnosis of central cyanosis in newborns because they cause cyanosis from birth.…”
Background
Cyanosis is usually associated with serious conditions requiring urgent treatment in the neonatal intensive care unit (NICU). Hemoglobin M (Hb M) disease is one type of congenital methemoglobinemia characterized by cyanosis. Among these variants, α-globin chain mutations such as Hb M Boston present cyanosis from birth while other variants usually manifest later in life.
Case presentation
We report a case of a male newborn with cyanosis apparent since birth. Surprisingly, his respiratory and hemodynamic status including normal arterial blood oxygen saturation was stable, but oxygen saturation on pulse oximetry did not increase after 100% supplemental oxygen was started. In addition to routine pulmonary and cardiologic evaluation, further evaluation for dyshemoglobin was conducted; α2-globin gene sequencing showed a single-point variant causing Hb M Boston. Methemoglobin (MetHb) level estimated by co-oximetry was normal. After a 14-day stay in the NICU, the patient remained respiratory and hemodynamically stable without supplemental oxygen except for cyanosis.
Conclusions
Hb M disease is a benign disease and does not require any treatment whereas acquired methemoglobinemia is a potentially fatal condition. Neonatologists should be aware that low oxygenation status on pulse oximetry in the face of normal arterial blood saturation values might indicate the possibility of Hb M disease in early neonatal cyanosis, irrespective of MetHb value.
“…Since chemical characterizations of Hb M were first reported in the late 1950s and early 1960s by Gerald [6, 7], the rare globin chain variants have been investigated by chromatography, electrophoresis, and gene sequencing [1, 2, 5].…”
Section: Discussionmentioning
confidence: 99%
“…Hb M caused by a mutation in α-, β-, or γ-globin can lead to spontaneous oxidation of the ferrous ion in the heme and cannot transport or release oxygen in tissues. Hb M disease causes cyanosis that is unresponsive to oxygen therapy [1, 2]. Some variants might need to be considered in the differential diagnosis of central cyanosis in newborns because they cause cyanosis from birth.…”
Background
Cyanosis is usually associated with serious conditions requiring urgent treatment in the neonatal intensive care unit (NICU). Hemoglobin M (Hb M) disease is one type of congenital methemoglobinemia characterized by cyanosis. Among these variants, α-globin chain mutations such as Hb M Boston present cyanosis from birth while other variants usually manifest later in life.
Case presentation
We report a case of a male newborn with cyanosis apparent since birth. Surprisingly, his respiratory and hemodynamic status including normal arterial blood oxygen saturation was stable, but oxygen saturation on pulse oximetry did not increase after 100% supplemental oxygen was started. In addition to routine pulmonary and cardiologic evaluation, further evaluation for dyshemoglobin was conducted; α2-globin gene sequencing showed a single-point variant causing Hb M Boston. Methemoglobin (MetHb) level estimated by co-oximetry was normal. After a 14-day stay in the NICU, the patient remained respiratory and hemodynamically stable without supplemental oxygen except for cyanosis.
Conclusions
Hb M disease is a benign disease and does not require any treatment whereas acquired methemoglobinemia is a potentially fatal condition. Neonatologists should be aware that low oxygenation status on pulse oximetry in the face of normal arterial blood saturation values might indicate the possibility of Hb M disease in early neonatal cyanosis, irrespective of MetHb value.
“…It was first characterized in the Iwate prefecture of Japan in 1960 where terms like 'black mouth', 'black blood' or 'black child' were used historically to denote the cyanosis in these individuals [2,8,9]. A few case reports have subsequently also been published from Europe [10,11,12], Turkey [13] and Brazil [14]. Hb M-Iwate was previously also christened as Hb M-Oldenburg, M-Kankakee and M-Sendai, all of which after molecular characterization were found to be the same variant [4,15,16].…”
“…Elsewhere, it was discovered that mutation of the R671 residue (that modulates the activity of early tryptic fragmentation) alters the conformation of the calcium pumps of SERCA 3 (Corvazier et al, 2009). In the haemoglobin molecule, genetic variants have been reported that cause cyanosis (a diminution in oxygen affinity) when the H58 residue is mutated (a variant known as Hb M Boston) (Nishikura et al, 1975;Viana and Belisário, 2014). Similarly, a further variant known as Hb Hornchurch shows a mutation in the E43 residue, which may be related to diminution in the plate count (thrombocytopenia) (Shi and Wang, 2017).…”
Section: Signal Transduction In Other Receptor-ligand Systemsmentioning
The coupling of a ligand with a molecular receptor induces a signal that travels through the receptor, reaching the internal domain and triggering a response cascade. In previous work on T-cell receptors and their coupling with foreign antigens, we observed the presence of planar molecular patterns able to generate electromagnetic fields within the proteins. These planes showed a coherent (synchronized) behavior, replicating immediately in the intracellular domain that which occurred in the extracellular domain as the ligand was coupled. In the present study, we examined this molecular transduction - the capacity of the coupling signal to penetrate deep inside the receptor molecule and induce a response. We verified the presence of synchronized behavior in diverse receptor-ligand systems. To appreciate this diversity, we present four biochemically different systems - TCR-peptide, calcium pump-ADP, haemoglobin-oxygen, and gp120-CD4 viral coupling. The confirmation of synchronized molecular transduction in each of these systems suggests that the proposed mechanism would occur in all biochemical receptor-ligand systems.
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