Adipose fatty acid composition in a case of generalized deficiency of cytochrome b5 reductase in congenital methemoglobinemia with mental retardation.

Lipids of liver, kidney, spleen and muscle in a case of generalized deficiency of cytochrome b5 reductase in congenital methemoglobinemia with mental retardation

“…As reported previously, there was a marked decrease in cerebrosides in white matter of the brain in a patient of generalized deficiency of cytochrome bs reductase in congenital methemoglobinemia with mental retardation (1). Lipid analysis also disclosed a lower level of linoleic acid and a higher level of palmitic acid in adipose tissue compared with the healthy control, showing that the patient continued to be in an underdeveloped condition (2).…”

“…Autopsy materials and analytical procedure were described earlier (1,2). The samples from normals were analyzed in the same laboratory using techniques identical to those used in the analysis of the patient's samples.…”

Ncb5or Deficiency Increases Fatty Acid Catabolism and Oxidative Stress

“…Unlike ⌬5 and ⌬6 desaturases from mammals (60, 61) and ⌬9 desaturase from bakers' yeast (62,63), SCDs in mammals have no intrinsic electron donor domain and, therefore, require a redox partner. Although Cyb5A and Cyb5R3 fulfill such a role in vitro, they are not obligate or exclusive redox partners for SCD because SCD index is mildly reduced in hepatic lipids of Cyb5A-null mice (10), in contrast to a greater reduction in Ncb5or-null (6) and in SCD-null mice (48), and no significant change is found in lipids of brain, kidney, or liver from patients with a methemoglobinemia-carrying mutation(s) in the Cyb5R3 or Cyb5A genes (64,65). It is also possible that Ncb5or cooperates with other redox partners and that Ncb5or deficiency indirectly impacts SCD functionality.…”

Cellular and Molecular Mechanisms of Recessive Hereditary Methaemoglobinaemia Type II

“…The molar proportion of cholesterol to phospholipids was hardly decreased in the myelin, and the cerebroside-to-phospholipids ratio was markedly reduced [ 22 ]. Furthermore, the unsaturated/saturated fatty acids ratio was slightly lower compared with healthy controls in both adipose tissue [ 23 ] and the liver [ 24 ]. These results evidenced an impaired lipid metabolism with an apparent central demyelination linked to type II RHM, but the reduction of unsaturated fatty acids (linoleic, linolenic, and arachidonic acids) was only 10% and the data came from a single patient.…”