MTR Gene

Definition:5-methyltetrahydrofolate-homocysteine methyltransferase

Official Symbol:MTR

 Chromosome:1


Gene Size: 105245 bp   235025341..235130585


No Exons:33

 Location : 1q43

Description:

MTR gene provides information for making an enzyme called methionine synthase.This enzyme, also known as cobalamin-dependent methionine synthase, catalyzes the final step in methionine biosynthesis

Disease :

Mutations in MTR have been identified as the underlying cause of methylcobalamin deficiency complementation group G,and Homocystinuria  Disease.In this disease more than 15 mutations in the MTR gene have been identified in people with homocystinuria. Many of these mutations lead to the production of an abnormally small, nonfunctional version of methionine synthase. Other mutations change single amino acids in the enzyme, which disrupts the enzyme's activity. For example, one of the most common mutations replaces the amino acid proline with the amino acid leucine at position 1173 (written as Pro1173Leu or P1173L). Without functional methionine synthase, homocysteine cannot be converted to methionine. As a result, homocysteine builds up in the bloodstream and methionine is depleted. Some of the excess homocysteine is excreted in urine. Researchers have not determined how altered levels of homocysteine and methionine lead to the health problems associated with homocystinuria.

MTHFR Gene

Definition:5,10-methylenetetrahydrofolate reductase (NADPH)

Official Symbol:MTHFR

Chromosome:1


Gene Size: 20329 bp complement(11768374..11788702)


No Exons:12

Location : 1p36.3



Description:

MTHFR gene codes for an enzyme called methylenetetrahydrofolate reductase,which plays vital role in amino acid processing and protein building blocks ,Methylenetetrahydrofolate reductase catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a cosubstrate for homocysteine remethylation to methionine

Disease :

Mutations in the gene MTHFR causes disease called Homocystinuria,Homocystinuria, also known as Cystathionine beta synthase deficiency, is an inherited disorder of the metabolism of the amino acid methionine, often involving cystathionine beta synthase. It is an inherited autosomal recessive trait, About 24 mutation in MTHFR gene have been identified in people with homocystinuria,Most of these mutaions are single amino acids in methylenetetrahydrofolate reductase.These substitutions disrupt the function of the enzyme, and may inactivate it completely,Without methylenetetrahydrofolate reductase, homocysteine cannot be converted to methionine. As a result, homocysteine builds up in the bloodstream and methionine is depleted. Some of the excess homocysteine is excreted in urine. Researchers have not determined how altered levels of homocysteine and methionine lead to the health problems associated with homocystinuria.

Homocystinuria, What is it?

MPZ - Myelin protein zero Gene

Definition:Myelin protein zero

Official Symbol:MPZ

Chromosome:1


Gene Size: 5227 bp (159541151..159546377)



No Exons:6


Location : 1q23.3




Description:

MPZ gene codes for making a protein called myelin protein zero, it is found abundant in the myelin sheath, the covering that protects nerves and promotes the efficient transmission of nerve impulses, Schwann cells are the only cells that produces myelin protein zero, This protein is required for the proper formation and maintenance of myelin, it acts like a molecular glue (adhesion molecule) and plays a role in tightly packing the myelin.

Disease:

Mutations in MPZ gene causes disease like Autosomal dominant form of Charcot-Marie-Tooth disease type 1 and other polyneuropathies, More than 100 mutations in MPZ gene causes a form of Charcot-Marie-tooth known as type 1B,These mutations alter the extracellular domain by replacing one of the building blocks (amino acids) in the myelin protein zero with incorrect amino acid, the altered myelin protein zero probably cannot interact properly with other myelin components, which disrupts the formation and maintenance of the myelin sheath, As a result, peripheral nerve cells cannot activate muscles used for movement or relay information from sensory cells back to the brain, causing the signs and symptoms of type 1B Charcot-Marie-Tooth disease.

MFN2 Mitofusin Gene

Definition:Mitofusin 2

Official Symbol:MFN2

Chromosome:1
Gene Size: 33197 bp (11962956..11996152)



No Exons:19


Location : 1p36.22

Description:This gene codes for a protein called mitofusin 2,This protein helps to determine the shape and structure of mitochondria during fission and fusion,This protein is involved in the regulation of vascular smooth muscle cell proliferation, and it may play a role in the pathophysiology of obesity

Disease :

Mutations in MFN2 gene cause disease like Charcot-Marie-Tooth disease (CMT disease)and Hereditary motor and sensory neuropathy VI,

In Charcot-Marie-Tooth disease Researchers have identified more than 30 MFN2 mutations,Almost all these mutations replace one of the protein building blocks in mitofusin 2 with an incorrect amino acid,As a result the mitofusin 2 protein are altered in critical region and cannot function properly,

Recent research showed that the mutated MFN2 causes mitochondria to form large clusters. In nerve cells these large clusters of mitochondria failed to travel down the axon towards the synapses. It is suggested these mitochondria clots make the synapses fail, resulting in CMT disease

MYOC Gene

Defintion:Myocilin, trabecular meshwork inducible glucocorticoid response

Official Symbol:MYOC

 Chromosome:1

 Location : 1q23-q24

Gene Size:17216 Bp  (169,871,179 to 169,888,395) Complement


No Exons:3

Description:

The MYOC gene provides instructions for producing a protein called myocilin. Myocilin is found in certain structures of the eye, called the trabecular meshwork and the ciliary body, that regulate the pressure within the eye (intraocular pressure). It is also found in various types of muscle. Myocilin's function is not well understood, but it may help to control the intraocular pressure through its action in the muscle tissue of the ciliary body.

Disease :
Early-onset glaucoma - caused by mutations in the MYOC gene
Approximately 10 percent to 33 percent of people with juvenile open-angle glaucoma have mutations in the MYOC gene. MYOC mutations have also been detected in some people with primary congenital glaucoma.

Mutations in the MYOC gene may alter the myocilin protein so that its interactions with other proteins are impeded. Defective myocilin that is not incorporated into functional complexes may accumulate in the trabecular meshwork and ciliary body. The excess protein may prevent sufficient flow of fluid from the eye, resulting in increased intraocular pressure and causing the signs and symptoms of early-onset glaucoma.

Individuals with mutations in both the MYOC and CYP1B1 genes may develop glaucoma at an earlier age than do those with mutations in only one of the genes.