Hereditary transthyretin (hATTR) amyloidosis, also known as variant ATTR (ATTRv) amyloidosis, is a rare disease affecting about 50,000 people worldwide. It's caused by a change (called a variant or mutation) in the gene which contains the instructions (or code) for making a protein called transthyretin (TTR). All humans have TTR, its job is to transport molecules around the body via the bloodstream. But in people who carry the variant or mutated gene, the TTR protein is abnormal and builds up as amyloid deposits in the organs, disrupting normal function and leading eventually to life-threatening organ failure. What's more, the disease can be passed down through families, sometimes with high frequency, meaning that generations of families are affected
