Hemoglobin FM-Viseu

Rare. Sporadic or dominant autosomal transmission of a mutation of the HBG2 gene (11p15.4), causing the replacement of Leu by Met in position 28 of the HbF gamma chain, which changes its three-dimensional configuration to position 63 and transforms it into methemoglobin. This results in neonatal cyanosis that responds poorly to oxygen therapy and for which no cardiac or respiratory causes can be identified. The cyanosis decreases and disappears progressively as HbF is replaced by HbA.


Anesthetic implications:

keep that possibility in mind in case of unexplained neonatal cyanosis, not responding to oxygenotherapy: arterial blood gases ! Transcutaneous paO2 monitoring.


References : 

-        Bento C, Maia TM, Carvalhais I, Moita F et al.
Transient neonatal cyanosis associated with a new HbF variant : HbF Viseu.
J Pediatr Hematol Oncol 2013; 35:e 77-80


Updated: January 2020