FADS2
Encyclopedia
Fatty acid desaturase 2 (FADS2) also known as delta(6) fatty acid desaturase (D6D) is an enzyme
that in humans is encoded by the FADS2 gene
.
s through the introduction of double bonds between defined carbons of the fatty acyl chain. FADS family members are considered fusion products composed of an N-terminal cytochrome b5
-like domain and a C-terminal multiple membrane-spanning desaturase portion, both of which are characterized by conserved histidine
motifs. This gene is clustered with family members FADS1
and FADS2 at 11q12-q13.1; this cluster is thought to have arisen evolutionarily from gene duplication based on its similar exon/intron organization.
such that breast-fed children with the "C" version of the gene appear about 7 intelligence quotient
(IQ) points higher than those with the less common "G" version (less than this when adjusted for maternal IQ).
An attempt to replicate this study in 5934 8 year old children failed: No relationship of the common C allele to negative effects of formula feeding was apparent, and contra to the original report, the rare GG homozygote children performed worse when formula fed than other children on formula milk. A study of over 700 families recently found no evidence for either main or moderating effects of the original SNP (rs174575), nor of two additional FADS2 polymorphisms (rs1535 and rs174583), nor any effect of maternal FADS2 status on offspring IQ.
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
that in humans is encoded by the FADS2 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
.
Function
Fatty acid desaturase 2 is a member of the fatty acid desaturase (FADS) gene family. Desaturase enzymes cause desaturation of fatty acidFatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
s through the introduction of double bonds between defined carbons of the fatty acyl chain. FADS family members are considered fusion products composed of an N-terminal cytochrome b5
Cytochrome b5
Cytochromes b5 are ubiquitous electron transport hemoproteins found in animals, plants, fungi and purple phototrophic bacteria. The microsomal and mitochondrial variants are membrane-bound, while bacterial and those from erythrocytes and other animal tissues are water-soluble...
-like domain and a C-terminal multiple membrane-spanning desaturase portion, both of which are characterized by conserved histidine
Histidine
Histidine Histidine, an essential amino acid, has a positively charged imidazole functional group. It is one of the 22 proteinogenic amino acids. Its codons are CAU and CAC. Histidine was first isolated by German physician Albrecht Kossel in 1896. Histidine is an essential amino acid in humans...
motifs. This gene is clustered with family members FADS1
FADS1
Fatty acid desaturase 1 is an enzyme that in humans is encoded by the FADS1 gene.- Function :The protein encoded by this gene is a member of the fatty acid desaturase gene family. Desaturase enzymes regulate unsaturation of fatty acids through the introduction of double bonds between defined...
and FADS2 at 11q12-q13.1; this cluster is thought to have arisen evolutionarily from gene duplication based on its similar exon/intron organization.
Clinical significance
It was reported the FADS2 interacts with breastfeedingBreastfeeding
Breastfeeding is the feeding of an infant or young child with breast milk directly from female human breasts rather than from a baby bottle or other container. Babies have a sucking reflex that enables them to suck and swallow milk. It is recommended that mothers breastfeed for six months or...
such that breast-fed children with the "C" version of the gene appear about 7 intelligence quotient
Intelligence quotient
An intelligence quotient, or IQ, is a score derived from one of several different standardized tests designed to assess intelligence. When modern IQ tests are constructed, the mean score within an age group is set to 100 and the standard deviation to 15...
(IQ) points higher than those with the less common "G" version (less than this when adjusted for maternal IQ).
An attempt to replicate this study in 5934 8 year old children failed: No relationship of the common C allele to negative effects of formula feeding was apparent, and contra to the original report, the rare GG homozygote children performed worse when formula fed than other children on formula milk. A study of over 700 families recently found no evidence for either main or moderating effects of the original SNP (rs174575), nor of two additional FADS2 polymorphisms (rs1535 and rs174583), nor any effect of maternal FADS2 status on offspring IQ.