The disease has been modelled in transgenic mice.[14] Dogs show a different phenotype from humans, with predominantly spinocerebellar ataxia.[15]
Neuropathology
Autopsy examination of eight cases has shown both developmental and degenerative neuropathologic features in this disease, consistent with clinical duality as both a neurodevelopmental and neurodegenerative disorder.[16]
In the central nervous system, accompanying the hypotonia at birth is hypoplasia of the corticospinal tracts. Another developmental feature is seen in the corpus callosum, which varies from absent to hypoplastic. The anterior commissure is almost always absent, but occasionally hypoplastic. A bundle of Probst can be found running anteroposterior rather than crossing the midline. The axonal damage due to the channel deficiency can cause a reactive axonal overgrowth leading to small, tumor-like growths, or tumorlets, called axonomas, or balls of aberrant axons attempting regrowth.[17] Damaged axons can also show a sign of inhibition of axonal transport, forming axonal spheroids. These spheroids can occur throughout the cerebral hemispheres, explaining the psychotic symptoms by disconnection of the brain from itself by axonal functional disruption.[16]
In the peripheral nervous system (PNS), the disease is more severe. While most nervous system diseases affect either central nervous system (CNS) or PNS, this disease affects both, but the changes in the PNS lead to death. This occurs by axonal disease paralyzing the skeletal muscles, including the respiratory muscles, as a result of axonal damage in peripheral nerves. Changes in the axons are more severe in the PNS than CNS, and under the electron microscope, some axons look necrotic, by virtue of containing mitochondrial flocculent densities and other irreversible changes.[16] The lack of innervation of the body musculature during development gives rise to small body weights, often below 40 kg (88 lb), remarkable in view of the preserved brain weights.[16]
Magnetic resonance imaging of the brain (revealing in 60% of the patients callosal agenesis and in 10% partial callosal agenesis)
Treatment
Currently, no cure is known, but some symptoms may be treated, such as neuroleptics for the psychiatric problems.[5]
Prognosis
The prognosis is poor. Patients are usually wheelchair bound by their 20s and die by their 30s.[4][5]
Prevalence
The prevalence rate has been estimated to be less than one per 1,000,000 worldwide,[4] and is much more common in the French-Canadian population of the Saguenay and Lac-St-Jean regions of Quebec, Canada, where it has a frequency of about one in 2100 in live births, and a carrier rate of one in 23.[5] This genetic disease, along with the SLC12A6 mutation, has also been described in Turkey,[19] Algeria,[20]Tanzania,[21] Bulgaria[22] and Norway.[23]
^ abcdDupré, Nicolas; Howard, Heidi C.; Rouleau, Guy A. (1993-01-01). "Hereditary Motor and Sensory Neuropathy with Agenesis of the Corpus Callosum". In Pagon, Roberta A.; Adam, Margaret P.; Ardinger, Holly H.; Wallace, Stephanie E.; Amemiya, Anne; Bean, Lora J.H.; Bird, Thomas D.; Ledbetter, Nikki; Mefford, Heather C. (eds.). GeneReviews. Seattle (WA): University of Washington, Seattle. PMID20301546.
^Andermann, E; Andermann, F; Joubert, M (1972). "Familial agenesis of the corpus callosum with anterior horn cell disease. A syndrome of mental retardation, areflexia and paraplegia". Transactions of the American Neurological Association. 97: 242-244.
^Andermann, E; Andermann, F; Joubert, D; Melançon, D; Karpati, G; Carpenter, S (1975). "Three familial midline malformation syndromes of the central nervous system: agenesis of the corpus callosum and anterior horn-cell disease; agenesis of cerebellar vermis; and atrophy of the cerebellar vermis". Birth Defects Original Article Series. 11 (2): 269–293. PMID1227532.
^Howard, HC; Mount, DB; Rochefort, D; Byun, N; Dupré, N; Lu, J; Fan, X; Song, L; Rivière, JB; Prévost, C; Horst, J; Simonati, A; Lemcke, B; Welch, R; England, R; Zhan, FQ; Mercado, A; Siesser, WB; George, AL Jr; McDonald, MP; Bouchard, J-P; Mathieu, J; Delpire, E; Rouleau, GA (2002). "The K-Cl cotransporter KCC3 is mutant in a severe peripheral neuropathy associated with agenesis of the corpus callosum". Nature Genetics. 32 (3): 384–392. doi:10.1038/ng1002. PMID12368912.
^Uyanik, G.; Elcioglu, N.; Penzien, J.; Gross, C.; Yilmaz, Y.; Olmez, A.; Demir, E.; Wahl, D.; Scheglmann, K. (2006). "Novel truncating and missense mutations of the KCC3 gene associated with Andermann syndrome". Neurology. 66 (7): 1044–1048. doi:10.1212/01.wnl.0000204181.31175.8b. ISSN1526-632X. PMID16606917. S2CID280621.
^Garneau, AP; Marcoux, AA; Frenette-Cotton, R; Mac-Way, F; Lavoie, JL; Isenring, P (2017). "Molecular insights into the normal operation, regulation, and multisystemic roles of K+-Cl- cotransporter 3 (KCC3)". American Journal of Physiology. Cell Physiology. 313 (5): C516 –C532. doi:10.1152/ajpcell.00106.2017. hdl:1866/33307. PMID28814402.
^Shekarabi, M; Salin-Cantegrel, A; Laganière, J; Gaudet, R; Dion, P; Rouleau, GA (2011). "Cellular expression of the K+-Cl- cotransporter KCC3 in the central nervous system of mouse". Brain Research. 1374: 15–26. doi:10.1016/j.brainres.2010.12.010. PMID21147077.
^Filteau, MJ; Pourcher, E; Bouchard, RH; Baruch, P; Mathieu, J; Bédard, F; Simard, N; Vincent, P (1991). "Corpus callosum agenesis and psychosis in Andermann syndrome". Archives of Neurology. 48 (12): 1275–1280. doi:10.1001/archneur.1991.00530240079027. PMID1668979.
^Larbrisseau, A; Vanasse, M; Brochu, P; Jasmin, G (1984). "The Andermann syndrome: agenesis of the corpus callosum associated with mental retardation and progressive sensorimotor neuronopathy". Canadian Journal of Neurological Sciences. 11 (2): 257–261. doi:10.1017/s0317167100045509. PMID6329500.
^Sung, JH (1987). "Tangled masses of central axons (central axonomas) in the brain stem: anatomical evidence for the regenerative growth of human central axons". Journal of Neuropathology and Experimental Neurology. 46 (2): 200–213. doi:10.1097/00005072-198703000-00007. PMID3819774.
^Demir, E; Irobi, J; Erdem, S; Demirci, M; Tan, E; Timmerman, V; De Jonghe, P; Topaloglu, H (2003). "Andermann syndrome in a Turkish patient". Journal of Child Neurology. 18 (1): 76–79. doi:10.1177/08830738030180011901. PMID12661946.
^Lesca, G; Cournu-Rebeix, I; Azoulay-Cayla, A; Lyon-Caen, Q; Barois, A; Dulac, O; Fontaine, B (2001). "Andermann syndrome in an Algerian family: suggestion of phenotype and genetic homogeneity". Revue Neurologique. 157 (10): 1279–1281. PMID11885521.
^Deleu, D; Bamanikar, SA; Muirhead, D; Louon, A (1997). "Familial progressive sensorimotor neuropathy with agenesis of the corpus callosum (Andermann syndrome): a clinical, neuroradiological and histopathological study". European Neurology. 37 (2): 104–109. doi:10.1159/000117419. PMID9058066.
^Pacheva, I; Todorov, T; Halil, Z; Yordanova, R; Todorova, A; Geneva, I; Galabova, F; Ivanov, I (2019). "First case of Roma ethnic origin with Andermann syndrome: A novel frameshift mutation in exon 20 of SLC12A6 gene". American Journal of Medical Genetics Part A. 179 (6): 1020–1024. doi:10.1002/ajmg.a.61110. PMID30868738.