CYB5R3 HOMOZYGOUS MUTATION AS A RARE CAUSE OF CYANOSIS IN THE NEWBORN

We present here a very illustrative case of a rare pathology of recessive congenital methemoglobinemia. The patient, a newborn female, has the variant NM_000398.7:c.535G>A, p.(Ala179Thr) of the CYB5R3 gene in homozygosis, a variant classified as pathogenic. The reported population frequency of the allele is 0.0128%, reason why it is remarkable to find both parents are heterozygous carriers without consanguinity. A brief review of previously published cases are presented.