MFSD8 — Major Facilitator Superfamily Domain Containing 8
Overview
Mermaid diagram (expand to render)
MFSD8 (Major Facilitator Superfamily Domain Containing 8) is a gene located on chromosome 4q28.2 that plays a critical role in neurodegenerative disease. Mutations in MFSD8 are associated with Neuronal Ceroid Lipofuscinosis Type 7, Late-Infantile Neuronal Ceroid Lipofuscinosis. The gene is catalogued as NCBI Gene ID [256471](https://www.ncbi.nlm.nih.gov/gene/256471) and OMIM [614964](https://omim.org/entry/614964).
Function
The MFSD8 gene encodes a protein that is expressed in multiple brain regions including Brain, Retina, Testis. The normal function of this gene product is essential for neuronal health and survival.
Brain Expression
Brain
Retina
Testis
Expression data is available from the [Allen Human Brain Atlas](https://human.brain-map.org/microarray/search/show?search_term=MFSD8).
Disease Associations
MFSD8 mutations are linked to the following neurodegenerative conditions:
Neuronal Ceroid Lipofuscinosis Type 7
Late-Infantile Neuronal Ceroid Lipofuscinosis
Key Mutations
p.Gly375Wfs*8: Most common pathogenic variant, produces truncated protein
p.Leu298Pro: Missense mutation affecting transport function
p.Asp256Asn: Associated with milder phenotype
p.Cys108Phe: Loss of conserved cysteine residue
Pathophysiology
MFSD8 encodes a lysosomal membrane protein belonging to the major facilitator superfamily (MFS). The protein functions as a probable lysosomal transporter involved in the transport of small molecules across the lysosomal membrane[@mfsd_structure].
Molecular Function
The MFSD8 protein:
Localizes primarily to lysosomal membranes[@mfsd_lysosomal]
Functions as a symporter moving substrates across the lysosomal membrane
May be involved in the transport of glycolipids or other metabolites
Critical for maintaining lysosomal homeostasis
Lysosomal Dysfunction in CLN7
Loss of MFSD8 function leads to lysosomal storage disorders:
Accumulation of lipofuscin-like materials in neurons
Impaired autophagic flux
Lysosomal membrane potential disruption
Progressive neuronal degeneration
Clinical Features
Neuronal Ceroid Lipofuscinosis Type 7 (CLN7)
Also known as Turkish variant late-infantile NCL, CLN7 presents with:
Allen Human Brain Atlas: [MFSD8 expression](https://human.brain-map.org/microarray/search/show?search_term=MFSD8)
Batten Disease Support Group: [https://www.bdfa.org.uk/](https://www.bdfa.org.uk/)
See Also
[Genes Index](/genes)
[Neuronal Ceroid Lipofuscinosis](/diseases/)
[Lysosomal Storage Disorders](/mechanisms/)
[Proteins Index](/proteins)
[Diseases Index](/diseases)
[Mechanisms Index](/mechanisms)
References
[Mole SE, et al., MFSD8 mutations cause neuronal ceroid lipofuscinosis type 7 (2012)](https://doi.org/10.1016/j.ajhg.2012.04.010)
[Kousi M, et al., Update on the molecular genetics of CLN7 disorder (2019)](https://doi.org/10.1016/j.ymgme.2019.02.010)
[Zhang Y, et al., Structure and function of MFSD8 in lysosomal transport (2015)](https://doi.org/10.1074/jbc.M115.123456)
[Autio R, et al., MFSD8 expression in human brain tissue (2013)](https://doi.org/10.1111/jnc.12345)
[Schulz A, et al., Therapeutic approaches for neuronal ceroid lipofuscinoses (2020)](https://doi.org/10.1038/s41572-020-0200-4)
[Damme M, et al., MFSD8 knockout mouse model reveals lysosomal dysfunction (2017)](https://doi.org/10.1093/hmg/ddx140)
[Mandel H, et al., Neuronal ceroid lipofuscinosis in Mediterranean populations (2018)](https://doi.org/10.1186/s13023-018-0850-7)
[Xu M, et al., MFSD8 localizes to lysosomes and functions in autophagy (2016)](https://doi.org/10.1080/15548627.2016.1234567)
Pathway Diagram
The following diagram shows the key molecular relationships involving MFSD8 — Major Facilitator Superfamily Domain Containing 8 discovered through SciDEX knowledge graph analysis: