Hereditary Amyloidosis can appear in many different clinical forms. A family history of the disease really helps diagnosis, but this has not been present in around half of the cases found in French families. Before there are signs of a developing axonal neuropathy, the diagnosis must be confirmed by evidence of amyloid deposits from a simple tissue biopsy (the salivary glands, subcutaneous fat) and by evidence of a pathological mutation found in an ATTR gene sequencing test. Genetic and histological confirmation is necessary, especially because heavy treatments like liver transplants might be necessary. If there is no family history of the disease, then diagnosis is difficult. This is the situation faced by half of the French families found to have the disease, particularly in cases where the disease is late-onset, i.e. after the age of 50. This type of amyloidosis often has a mix of symptoms (cardiological and neurological) but it can be the case that just the heart is affected. In cases like this, the biopsy is necessary to detect amyloid deposits and confirm the diagnosis. If histological tests confirm that it is amyloidosis, the diagnosis must then be further refined by an ATTR gene sequencing test and further blood and urine tests. The objective is to identify the type of amyloidosis (AL, TTR, AA) and guide treatment because this can differ greatly from case to case.