This is true, but more often than not, it’s from exposure to chemicals and the body lacking the gene for successful methylation. My entire family has MCS, and I know another family where all 6 kids have it at various stages. MCS is the fastest growing illness now all over the world. People need to stop buying scented toxic laundry/cleaning products and calling the house “clean”. It’s crazy what advertising has done to the public in convincing people their homes are dirty unless using these fragrance chemicals! Ugh 😑