PMM2 deficiency | |
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Other names | Carbohydrate-deficient Glycoprotein Syndrome (CDGS) Type Ia, Congenital Disorder of Glycosylation (CDG) Type Ia,Phosphomannomutase Deficiency [1] ,Jaeken Syndrome, PMM2-CDG , CDG1a |
PMM2 protein |
PMM2 deficiency or PMM2-CDG, previously CDG-Ia, is a very rare genetic disorder caused by mutations in PMM2 . It is an autosomal recessive disease that is the most common type of congenital disorder of glycosylation or CDG. [2] PMM2-CDG is the most common of a growing family of more than 130 extremely rare inherited metabolic disorders. [3] Only about 800 children and adults have been reported worldwide. [4]
PMM2 deficiency is diagnosed through genetic sequencing. More than 115 mutations in the PMM2 gene have been found to cause this disease. [16]
Treatment with mannose powder 1 to 2 g / kg per day results in significant improvement in protein glycosylation after 1 year. [17] Other treatments involve management of the symptoms that are apparent in each individual, including physical therapy to improve core strength and mobility, occupational therapy for coordination, speech therapy for talking and eating. [13]
A glycogen storage disease is a metabolic disorder caused by a deficiency of an enzyme or transport protein affecting glycogen synthesis, glycogen breakdown, or glucose breakdown, typically in muscles and/or liver cells.
A congenital disorder of glycosylation is one of several rare inborn errors of metabolism in which glycosylation of a variety of tissue proteins and/or lipids is deficient or defective. Congenital disorders of glycosylation are sometimes known as CDG syndromes. They often cause serious, sometimes fatal, malfunction of several different organ systems in affected infants. The most common sub-type is PMM2-CDG where the genetic defect leads to the loss of phosphomannomutase 2 (PMM2), the enzyme responsible for the conversion of mannose-6-phosphate into mannose-1-phosphate.
Microcephaly is a medical condition involving a smaller-than-normal head. Microcephaly may be present at birth or it may develop in the first few years of life. Brain development is often affected; people with this disorder often have an intellectual disability, poor motor function, poor speech, abnormal facial features, seizures and dwarfism.
Phosphoglucomutase is an enzyme that transfers a phosphate group on an α-D-glucose monomer from the 1 to the 6 position in the forward direction or the 6 to the 1 position in the reverse direction.
Sanfilippo syndrome, also known as mucopolysaccharidosis type III (MPS III), is a rare autosomal recessive lysosomal storage disease that primarily affects the brain and spinal cord. It is caused by a buildup of large sugar molecules called glycosaminoglycans (AKA GAGs, or mucopolysaccharides) in the body's lysosomes.
Menkes disease (MNK), also known as Menkes syndrome, is an X-linked recessive disorder caused by mutations in genes coding for the copper-transport protein ATP7A, leading to copper deficiency. Characteristic findings include kinky hair, growth failure, and nervous system deterioration. Like all X-linked recessive conditions, Menkes disease is more common in males than in females. The disorder was first described by John Hans Menkes in 1962.
Congenital muscular dystrophies are autosomal recessively-inherited muscle diseases. They are a group of heterogeneous disorders characterized by muscle weakness which is present at birth and the different changes on muscle biopsy that ranges from myopathic to overtly dystrophic due to the age at which the biopsy takes place.
Phosphomannomutase 2 is an enzyme that in humans is encoded by the PMM2 gene.
Dolichyl pyrophosphate Man9GlcNAc2 alpha-1,3-glucosyltransferase is an enzyme that in humans is encoded by the ALG6 gene.
Phosphomannomutase 1 is an enzyme that in humans is encoded by the PMM1 gene.
Alpha-1,3/1,6-mannosyltransferase ALG2 is an enzyme that is encoded by the ALG2 gene. Mutations in the human gene are associated with congenital defects in glycosylation The protein encoded by the ALG2 gene belongs to two classes of enzymes: GDP-Man:Man1GlcNAc2-PP-dolichol alpha-1,3-mannosyltransferase and GDP-Man:Man2GlcNAc2-PP-dolichol alpha-1,6-mannosyltransferase.
Dolichol-phosphate mannosyltransferase is an enzyme that in humans is encoded by the DPM1 gene.
Dolichyl-P-Man:Man(7)GlcNAc(2)-PP-dolichyl-alpha-1,6-mannosyltransferase is an enzyme that in humans is encoded by the ALG12 gene.
Dolichyl-P-Man:Man(5)GlcNAc(2)-PP-dolichyl mannosyltransferase is an enzyme that, in humans, is encoded by the ALG3 gene.
Dolichol kinase deficiency is a cutaneous condition caused by a mutation in the dolichol kinase gene.
MURCS association is a very rare developmental disorder that primarily affects the reproductive and urinary systems involving MUllerian agenesis, Renal agenesis, Cervicothoracic Somite abnormalities. It affects only females.
Cerebral folate deficiency is a condition in which concentrations of 5-methyltetrahydrofolate are low in the brain as measured in the cerebral spinal fluid despite being normal in the blood. Symptoms typically appear at about 5 to 24 months of age. Without treatment there may be poor muscle tone, trouble with coordination, trouble talking, and seizures.
SRD5A3-CDG is a rare, non X-linked congenital disorder of glycosylation (CDG) due to a mutation in the steroid 5 alpha reductase type 3 gene. It is one of over 150 documented types of Congenital disorders of Glycosylation. Like many other CDGs, SRD5A3 is ultra-rare, with around 38 documented cases in the world.
SLC35A1-CDG is a rare inherited disorder that mainly affects the vascular systems of the body. It forms part of a large group of disorders called congenital disorders of glycosylation. It is caused by mutations in the SLC35A1 gene, located in the sixth chromosome.
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