Catalyzes the specific attachment of an amino acid to its cognate tRNA in a 2 step reaction: the amino acid (AA) is first activated by ATP to form AA-AMP and then transferred to the acceptor end of the tRNA

Cytoplasm, cytosol

Hypomyelination with brainstem and spinal cord involvement and leg spasticity

An autosomal recessive leukoencephalopathy characterized by onset in the first year of life of severe spasticity, mainly affecting the lower limbs and resulting in an inability to achieve independent ambulation. Affected individuals show delayed motor development and nystagmus; some may have mild intellectual disability. Brain MRI shows hypomyelination and white matter lesions in the cerebrum, brainstem, cerebellum, and spinal cord.

Accessory subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I), that is believed not to be involved in catalysis. Complex I functions in the transfer of electrons from NADH to the respiratory chain. The immediate electron acceptor for the enzyme is believed to be ubiquinone

Mitochondrion inner membrane

Mitochondrial complex I deficiency, nuclear type 13

A form of mitochondrial complex I deficiency, the most common biochemical signature of mitochondrial disorders, a group of highly heterogeneous conditions characterized by defective oxidative phosphorylation, which collectively affects 1 in 5-10000 live births. Clinical disorders have variable severity, ranging from lethal neonatal disease to adult-onset neurodegenerative disorders. Phenotypes include macrocephaly with progressive leukodystrophy, non-specific encephalopathy, cardiomyopathy, myopathy, liver disease, Leigh syndrome, Leber hereditary optic neuropathy, and some forms of Parkinson disease. MC1DN13 transmission pattern is consistent with autosomal recessive inheritance.

Transcription factor with repressor activity involved in the regulation of axon-glial interactions at myelin paranodes in oligodendrocytes. Binds to the consensus DNA sequence 5'-(A/T)TTAATGA-3'. In oligodendrocytes, binds to MBP and PLP1 promoter regions

Nucleus

Spastic ataxia 8, autosomal recessive, with hypomyelinating leukodystrophy

An autosomal recessive neurodegenerative disorder characterized by early-onset hypotonia which progresses to a pyramidal syndrome with ataxia, spasticity, hyperreflexia, weakness and loss of ambulation. Brain imaging shows cerebellar atrophy and hypomyelinating leukodystrophy.

Major component of the axial/lateral elements of synaptonemal complexes (SCS) during meiotic prophase. Plays a role in the assembly of synaptonemal complexes. Required for normal meiotic chromosome synapsis during oocyte and spermatocyte development and for normal male and female fertility. Required for insertion of SYCP3 into synaptonemal complexes. May be involved in the organization of chromatin by temporarily binding to DNA scaffold attachment regions. Requires SYCP3, but not SYCP1, in order

NucleusChromosome

Spermatogenic failure 1

An infertility disorder characterized by azoospermia due to spermatogenic arrest during meiosis. Meiotic arrest is characterized by germ cells that enter meiosis and undergo the first chromosomal reduction from 4n to 2n, but that are then unable to proceed further. This results in tubules containing spermatocytes as the latest developmental stage of germ cells. Meiotically arrested spermatocytes accumulate in the tubules and degenerate. Both autosomal recessive and autosomal dominant inheritance have been reported.

Catalyzes the oxidation of medium and long chain aliphatic aldehydes to fatty acids. Active on a variety of saturated and unsaturated aliphatic aldehydes between 6 and 24 carbons in length (PubMed:18035827, PubMed:18182499, PubMed:22633490, PubMed:25047030, PubMed:9133646, PubMed:9662422). Responsible for conversion of the sphingosine 1-phosphate (S1P) degradation product hexadecenal to hexadecenoic acid (PubMed:22633490)

Microsome membraneEndoplasmic reticulum membrane

Sjoegren-Larsson syndrome

An autosomal recessive neurocutaneous disorder characterized by a combination of severe intellectual disability, spastic di- or tetraplegia and congenital ichthyosis. Ichthyosis is usually evident at birth with varying degrees of erythema and scaling, neurologic symptoms appear in the first or second year of life. Most patients have an IQ of less than 60. Additional clinical features include glistening white spots on the retina, seizures, short stature and speech defects.

Mitochondrial NAD(+) kinase that phosphorylates NAD(+) to yield NADP(+). Can use both ATP or inorganic polyphosphate as the phosphoryl donor. Also has weak NADH kinase activity in vitro; however NADH kinase activity is much weaker than the NAD(+) kinase activity and may not be relevant in vivo

Mitochondrion

2,4-dienoyl-CoA reductase deficiency

A rare, autosomal recessive, inborn error of polyunsaturated fatty acids and lysine metabolism, resulting in mitochondrial dysfunction. Affected individuals have a severe encephalopathy with neurologic and metabolic abnormalities beginning in early infancy. Laboratory studies show increased C10:2 carnitine levels and hyperlysinemia.

Acts as a component of the translation initiation factor 2B (eIF2B) complex, which catalyzes the exchange of GDP for GTP on eukaryotic initiation factor 2 (eIF2) gamma subunit (PubMed:25858979, PubMed:27023709, PubMed:31048492). Its guanine nucleotide exchange factor activity is repressed when bound to eIF2 complex phosphorylated on the alpha subunit, thereby limiting the amount of methionyl-initiator methionine tRNA available to the ribosome and consequently global translation is repressed (Pub

Cytoplasm, cytosol

Leukoencephalopathy with vanishing white matter 4

An autosomal recessive brain disease characterized by neurological features including progressive cerebellar ataxia, spasticity, and cognitive deficits. Brain imaging shows abnormal white matter that vanishes over time and is replaced by cerebrospinal fluid. Disease severity ranges from fatal infantile forms to adult forms without neurological deterioration. The disease is progressive with, in most individuals, additional episodes of rapid deterioration following febrile infections or minor head trauma. Death may occurs after a variable period after disease onset, usually following an episode of fever and coma. A subset of affected females with milder forms of the disease who survive to adolescence exhibit ovarian dysfunction. This variant of the disorder is called ovarioleukodystrophy.

Transmembrane protein mainly expressed in brain astrocytes that may play a role in transport across the blood-brain and brain-cerebrospinal fluid barriers (PubMed:22328087). Regulates the response of astrocytes to hypo-osmosis by promoting calcium influx (PubMed:22328087). May function as regulatory protein of membrane protein complexes such as ion channels (Probable)

MembraneCell membraneCytoplasm, perinuclear regionEndoplasmic reticulum

Megalencephalic leukoencephalopathy with subcortical cysts 1

A syndrome of cerebral leukoencephalopathy and megalencephaly characterized by ataxia, spasticity, seizures, delay in motor development and mild intellectual disability. The brain appears swollen on magnetic resonance imaging, with diffuse white-matter abnormalities and the invariable presence of subcortical cysts in frontal and temporal lobes.

Involved in peroxisomal proliferation (PubMed:9792670). May regulate peroxisome division by recruiting the dynamin-related GTPase DNM1L to the peroxisomal membrane (PubMed:12618434). Promotes membrane protrusion and elongation on the peroxisomal surface (PubMed:20826455)

Peroxisome membrane

Peroxisome biogenesis disorder 14B

An autosomal recessive peroxisome biogenesis disorder characterized clinically by mild intellectual disability, congenital cataracts, progressive hearing loss, and polyneuropathy. Additionally, recurrent migraine-like episodes following mental stress or physical exertion, not a common feature in peroxisome disorders, are observed.

Necessary for early peroxisomal biogenesis. Acts both as a cytosolic chaperone and as an import receptor for peroxisomal membrane proteins (PMPs). Binds and stabilizes newly synthesized PMPs in the cytoplasm by interacting with their hydrophobic membrane-spanning domains, and targets them to the peroxisome membrane by binding to the integral membrane protein PEX3. Excludes CDKN2A from the nucleus and prevents its interaction with MDM2, which results in active degradation of TP53

CytoplasmPeroxisome membrane

Peroxisome biogenesis disorder complementation group 14

A peroxisomal disorder arising from a failure of protein import into the peroxisomal membrane or matrix. The peroxisome biogenesis disorders (PBD group) are genetically heterogeneous with at least 14 distinct genetic groups as concluded from complementation studies. Include disorders are: Zellweger syndrome (ZWS), neonatal adrenoleukodystrophy (NALD), infantile Refsum disease (IRD), and classical rhizomelic chondrodysplasia punctata (RCDP). ZWS, NALD and IRD are distinct from RCDP and constitute a clinical continuum of overlapping phenotypes known as the Zellweger spectrum (PBD-ZSS).

Catalyzes the deacetylation of N-acetylaspartic acid (NAA) to produce acetate and L-aspartate. NAA occurs in high concentration in brain and its hydrolysis NAA plays a significant part in the maintenance of intact white matter. In other tissues it acts as a scavenger of NAA from body fluids

CytoplasmNucleus

Canavan disease

A rare neurodegenerative condition of infancy or childhood characterized by white matter vacuolization and demyelination that gives rise to a spongy appearance. The clinical features are onset in early infancy, atonia of neck muscles, hypotonia, hyperextension of legs and flexion of arms, blindness, severe mental defect, megalocephaly, and death by 18 months on the average.