Nipa‐Like Domain‐Containing 4, also known as NIPAL4 or Ichthyin, is a gene that is predicted to code for a transmembrane protein with nine transmembrane domains.[5]NIPAL4 codes for the protein magnesiumtransporter NIPA4, which acts as a Mg2+ transporter.
NIPAL4 is mainly expressed in the skin, specifically in the granular layer of the epidermis.[6]
Function[]
NIPAL4 codes for a magnesium transporter that can also transport other divalent cations such as Ba2+, Mn2+, Sr2+ and Co2+, though to a much less extent than Mg2+.[5] There is also evidence that NIPAL4 is involved in the synthesis of very long chain fatty acids involved in the epidermal lipid metabolism.[7] Disruptions to this pathway results in impaired skin function, causing the symptoms of ARCI.[8]
Pathology[]
Mutations in this gene account for 16% of autosomal recessive congenital ichthyosis (ARCI) cases, making it the 2nd most common gene involved with this disease.[9] Since its first identification in 2004, 18 disease‐causing mutations have been reported in NIPAL4.[8]