Soil water status as a function of pressure (tension). Soil water status in natural soils can range from a flooded. condition to drainable gravitational water to plant available water. down to hydroscopic water. Tensions in natural soils do not. exceed -31,000; in this range, water is absorbed from the air.
Advanced Search. Tay-Sachs disease (the most severe form of Hexosaminidase A deficiency) is a progressive, fatal genetic condition that affects the nerve cells in the brain.
A defective gene on chromosome 15 causes Tay-Sachs disease. This defective gene causes the body to not make a protein called hexosaminidase A. Without this protein, chemicals called gangliosides build up in nerve cells in the brain, destroying brain cells.