This report describes neuronal ceroid lipofuscinosis 7 (NCL7), which is a subtype of neuronal ceroid lipofuscinosis; NCL7 exhibits autosomal recessive inheritance. The human gene implicated in this disease is MFSD8 (major facilitator superfamily domain containing 8), a ubiquitous integral membrane protein that is presumed to function as a transporter; there is evidence that the protein localizes to lysosomal membranes. There is a single orthologous gene is Drosophila, Dmel\Cln7, for which RNAi-targeting constructs have been generated. The MFSD8 gene is also implicated in a second disease, Macular dystrophy with central cone involvement (MIM:616170).
The human MFSD8 gene has not been introduced into flies.
The Drosophila Cln7 gene is a recent subject of investigation; mutations cause neurodevelopmental defects. A YFP-fusion construct has allowed visualization of protein distribution. In Drosophila, this protein has restricted expression: it is detected in the larval CNS, predominantly in the glia that form the insect blood-brain-barrier; it is also expressed in neurons in the developing visual system.
[updated Dec. 2017 by FlyBase; FBrf0222196]
The neuronal ceroid lipofuscinoses (NCLs or CLNs) are a clinically heterogeneous group of neurodegenerative disorders; the general clinical course includes progressive dementia, seizures, and progressive visual failure (Mole et al., 2005; pubmed:15965709). [from MIM:256730; 2016.01.05]
Individuals with all forms NCL have shortened life expectancy, but it is highly variable, depending upon the form of the disease (from Medscape, http://emedicine.medscape.com/article/1178391-overview; 2016.01.05).
The term Batten disease may refer specifically to the juvenile-onset form, but is also used to refer to any NCL.
[CEROID LIPOFUSCINOSIS, NEURONAL, 7; CLN7](https://omim.org/entry/610951)
[MAJOR FACILITATOR SUPERFAMILY DOMAIN-CONTAINING PROTEIN 8; MFSD8](https://omim.org/entry/611124)
NCL7 is typically characterized by late-infantile onset of symptoms (seizures or motor impairment followed by mental regression, myoclonus, speech impairment, loss of vision, and personality disorders). [DOID:0110722; 2017.12.21]
See general description, above.
Neuronal ceroid lipofuscinosis-7 (CLN7) is caused by homozygous or compound heterozygous mutation in the MFSD8 gene. [from MIM:610951; 2017.12.21]
MFSD8 encodes a ubiquitous integral membrane protein that contains a transporter domain and a major facilitator superfamily (MFS) domain. The substrate transported by this protein is unknown. The protein likely localizes to lysosomal membranes. [Gene Cards, MFSD8; 2017.12.21]
Major facilitator superfamily (MFS) transporters move a variety of small compounds across biological membranes.
MFSD8 (major facilitator superfamily domain-containing protein 8)encodes a putative lysosomal transporter. [from MIM:610951; 2017.12.21]
One to one (1 human to 1 Drosophila).
High-scoring ortholog of human MFSD8 (1 Drosophila to 1 human); Dmel\Cln7 shares 35% identity and 57% similarity with the human gene.
