Study reported in PLoS Genetics says AP1S1 mutation causes MEDNIK.
Researchers have announced the discovery of MEDNIK syndrome, an incapacitating genetic condition. They report that this syndrome is caused by a newly found mutation in the Adaptor-related protein complex 1, sigma 1 subunit (AP1S1) gene.
MEDNIK was identified in a group of families in Quebec from the Kamouraska region sharing a common ancestor. It is characterized by mental retardation, enteropathy, deafness, and peripheral neuropathy, ichthyosis, and keratodermia.
“’Our observations strongly suggest that MEDNIK syndrome is caused by impaired development of various neural networks, including the spinal cord (ataxia and neuropathy), the inner ear (sensorineural deafness), and possibly the brain (microcephaly and psychomotor retardation),” explains Patrick Cossette, from the Universitr de Montreal Hospital Research Centre. “Disruption of the AP1S1 gene in humans may be associated with more widespread perturbation in the development of various organs, including the gut and the skin.”
The scientists, using zebrafish as an animal model, observed that the loss of the AP1S1 gene resulted in the aforementioned broad defects including severe motor deficits due to impairment of spinal cord development. By inducing the expression of the human AP1S1 gene instead of the zebrafish gene, the research team found that the normal human type could rescue these developmental deficits but not the AP1S1 gene bearing the disease-related mutation.
Investigators from various Canadian institutes were involved in this study. The results appear in the online version of PLoS Genetics.