ANO5

The ANO5 gene provides instructions for making a protein called anoctamin-5. While the specific function of this protein is not well understood, it belongs to a family of proteins, called anoctamins, that act as chloride channels. Chloride channels, which transport negatively charged chlorine atoms (chloride ions) in and out of cells, play a key role in a cell's ability to generate and transmit electrical signals. Most anoctamin proteins function as chloride channels that are turned on (activated) in the presence of positively charged calcium atoms (calcium ions); these channels are known as calcium-activated chloride channels. The mechanism for this calcium activation is unclear. Anoctamin proteins are also involved in maintaining the membrane that surrounds cells and repairing the membrane if damaged.[5]

The anoctamin-5 protein is most abundant in muscles used for movement (skeletal muscles). For the body to move normally, skeletal muscles must tense (contract) and relax in a coordinated way. The regulation of chloride flow within muscle cells plays a role in controlling muscle contraction and relaxation.[5]

The anoctamin-5 protein is also found in other cells including heart (cardiac) muscle cells and bone cells. The anoctamin-5 protein may be important for the development of muscle and bone before birth.[5]

• Gnathodiaphyseal dysplasia (GDD), a rare skeletal syndrome.[6]
• Limb Girdle Muscular Dystrophy 2L (LGMD2L, Autosomal Recessive 12)[6][7] and Miyoshi Muscular Dystrophy 3 (MMD3).[6] These forms of muscular dystrophy are inherited in an autosomal recessive pattern. To be affected, a person must have mutations on both copies of the gene. Males and females are equally likely to be affected.

GDD causes bone fragility, sclerosis of tubular bones, and cemento-osseous lesions of the jawbone. Patients also experience frequent bone fractures.[6]

Clinically, LGMD2L and MMD3 were considered different diseases before ANO5 was identified as the responsible gene; LGMD was used to describe initial weakness in proximal muscles (hip and shoulder girdles) while MMD described initial weakness in the distal muscles of the lower limbs.[6]

• ANO5_HUMAN
• anoctamin-5
• GDD1
• gnathodiaphyseal dysplasia 1 protein
• integral membrane protein GDD1
• LGMD2L
• TMEM16E
• transmembrane protein 16E[5]

• Cytogenetic location: 11p14.3, which is the short (p) arm of chromosome 11 at position 14.3
• Molecular location: base pairs 22,192,485 to 22,283,367 on chromosome 11 (Homo sapiens Annotation Release 109, GRCh38.p12) (NCBI)

Credit: Genome Decoration Page/NCBI

• LGMD2L Foundation
• Myonexus Therapeudics
• Online Mendelian Inheritance in Man (OMIM): MUSCULAR DYSTROPHY, LIMB-GIRDLE, TYPE 2L; LGMD2L - 611307
• Novel ANO5 KO mouse provides new insight into LGMD2L pathogenesis
• wolframalpha ano5