congenital methemoglobinemia is a rare cause of cyanosis. we report a case of a girl, 17 years old with peripheral cyanosis and normal cardio-pulmonary system. she was diagnosed as a case of methemoglobinemia based on findings of polycythemia and hbm band on hemoglobin electrophoresis. we emphasize the importance of this rare entity in the differential diagnosis of cyanosis.

Congenital methemoglobinemia is a rare cause of cyanosis. We report a case of a girl, 17 years old with peripheral cyanosis and normal cardio-pulmonary system. She was diagnosed as a case of methemoglobinemia based on findings of polycythemia and HbM band on hemoglobin electrophoresis. We emphasize the importance of this rare entity in the differential diagnosis of cyanosis.

The reduction of hemoglobins (Hb) M such as Hb M Iwate, Hb M Boston, Hb M Hyde Park, Hb M Saskatoon, and Hb M Milwaukee by the ferredoxin and ferredoxin-NADP reductase system was studied systematically under anaerobic conditions. The enzyme system could not reduce the abnormal chains in methemoglobin M with an alpha chain anomaly but effectively converted the methemoglobin M with a beta chain a...

Methemoglobin (Hb-M) is a rare hemoglobinopathy in China. We hereby report on a family living in Yantai, East China, with congenital cyanosis due to Hb-M mutation. The proband, a 65-year-old female, presented 63% oxygen saturation. Both Hb-M concentration and arterial oxygen saturation remained unchanged, even following intravenous treatment with methylene blue. There was also no change in bloo...

Haemoglobin (Hb)-M Hyde Park, also known as Hb-M Akita is a rare type of hereditary Hb M due to autosomal dominant mutation of CAC>TAC on codon 92 of β globin gene resulting in the replacement of histidine by tyrosine on β globin chain. This variant Hb has a tendency to form methaemoglobin (metHb). The iron ion in metHb is oxidized to ferric (Fe3+) which is unable to carry oxygen and the patien...

By BENNETT F. HORTON, ROBERT B. THOMPSON, ANDREE M. Dozy, CARL M. NECHTMAN, EVAN NIcHOLs AND TITUS H. J. HUISMAN D URING the past few years, some human hemoglobins have been found composed of one single type of polypeptide chain in contrast to the more common hemoglobins, composed of two types of polypeptide chains. The most important of these are Hb-Bart’s, composed of four of the y chains of ...

We found that deoxy Hb A aggregated or formed gels with a clear exhibition of a delay time when a solution of deoxy Hb A with a concentration of 120% of its solubility was incubated at 30°C. Since the solubility of deoxy Hb A is much higher than that of deoxy Hb S, this condition was created by increasing the phosphate concentration. The length of the delay and aggregation times and the amounts...