Familial Amyloid Polyneuropathy of the Portuguese type

By Dr.Theodoros Kyriakides, neurologist (honorary member of the Association)

Familial amyloid polyneuropathy of the Portuguese type (TTR-Met30) is a rare hereditary condition that was possibly brought to the island and started affecting locals during the 3^rd Crusade.  It appears, on average, around 40, in both men and women and infects people with a particular gene mutation in their transthyretin gene. Beyond neuropathic symptoms (such as muscle weakness and atrophy, difficulty in feeling hot and cold water, mostly in the lower extremities), patients also suffer gastrointestinal, urogenital and blood circulation problems, as well as complications to their kidneys and eyes. If not treated at all, in a decade the patient will be unable to walk unassisted and will eventually die from heart failure and weight loss.

At an international level, most cases of TTR-Met30 are found in Portugal, Italy, France, northern Sweden and Japan, while in Greece, the majority of patients have been reported in Crete. Cyprus is one of the European countries with increasing frequency, with those diagnosed being treated and monitored by the Institute of Neurology and Genetics. More often than not, patients are not well informed about symptomatology and suffer unnecessary frustration, discomfort and delays, until the right diagnosis is made.

Anyone with a family history of TTR-Met30, but also those who are unaware of familial conditions, but suffer from progressive neuropathy with acute attacks of pins and needles and loss of hot-cold sensation in their soles, should undergo genetic tests at the Institute of Neurology and Genetics. This is even more necessary for Limassol and Keryneia district patients.

So far, the only way of keeping the progression of the illness in check was a liver transplant, as the organ produces transthyretin, the mutated protein that is deposited in the peripheral nerves, causing the onset of the condition.

In recent years however, there have been significant developments in the way TTR-Met30 is treated. Since 2011, mouth received medicine is available. Tafamidis is the only approved drug in Europe that can delay the development of toxic mutated protein in peripheral nerves, heart and kidneys. Tafamidis has been approved by the European Medicines Agency for patients on a liver transplant list. It can be several months before a liver is found and their health deteriorates during this time. In certain countries including Portugal, many patients decide to continue taking Tafamidis instead of going through with a transplant, as the response of their body to the medicine is effective and the condition is stabilized, its progression prevented. In addition, patients spare themselves from transplant complications, including organ rejection, leading to post-surgery death.

The numbers are very positive in the four years of Tafamidis use in Europe. Hundreds of patients have benefited, as the drug has shown good results in suspending the progression of the condition and improving quality of life.