PI4KA
Function
Acts on phosphatidylinositol (PtdIns) in the first committed step in the production of the second messenger inositol-1,4,5,-trisphosphate.
Involvement in disease
Neurodevelopmental disorder with spasticity, hypomyelinating leukodystrophy, and brain abnormalities
NEDSPLB
A severe autosomal recessive disorder characterized by global developmental delay with impaired intellectual development and poor or absent speech, axial hypotonia, and peripheral spasticity and hyperreflexia. Brain imaging shows hypomyelination with decreased white matter volume, cerebral and cerebellar atrophy, and thin corpus callosum. Polymicrogyria may be observed in rare cases. Some patients have a primary immunodeficiency or gastrointestinal disturbances similar to inflammatory bowel disease.
None
The disease is caused by variants affecting the gene represented in this entry.
Gastrointestinal defects and immunodeficiency syndrome 2
GIDID2
A severe autosomal recessive disorder characterized by multiple intestinal atresia apparent soon after birth. Affected infants have a distended abdomen, bowel obstruction and do not pass meconium. There is some evidence of inflammatory bowel disease. Death occurs in the first weeks of life. Some patients may also have immunodeficiency.
None
The disease is caused by variants affecting the gene represented in this entry.
Spastic paraplegia 84, autosomal recessive
SPG84
A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body. SPG84 is characterized by onset of slowly progressive walking difficulties due to lower limb weakness, stiffness, and spasticity in the first 2 decades of life.
None
The disease is caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the PI3/PI4-kinase family. Type III PI4K subfamily.
Tissue Specificity
Expressed ubiquitously. Highest levels in placenta and brain. Little or no expression in lung, liver, pancreas, testis or leukocytes.
Cellular localization
- Cytoplasm
- Cell membrane
- Localization to the plasma membrane is mediated by the PI4K complex and association with EFR3 (EFR3A or EFR3B), TTC7 (TTC7A or TTC7B) and HYCC (HYCC1 or HYCC2) (PubMed:23229899). Localization to the plasma membrane is regulated by TMEM150A (PubMed:25608530).
Alternative names
PIK4, PIK4CA, PI4KA, Phosphatidylinositol 4-kinase alpha, PI4-kinase alpha, PI4K-alpha, PtdIns-4-kinase alpha, Phosphatidylinositol 4-Kinase III alpha