All three variants showed aberrant banding patterns that were similar to those of other well-characterized TTR variants, including the common Val30Met variant that causes ATTR amyloidosis.
Although CTS associated with TTR amyloidosis has been known as an initial symptom in some patients with ATTR non-Val30Met FAP and those with senile systemic amyloidosis, this is the first report of ATTR Val30Met FAP patients starting with upper limb neuropathy including CTS-like symptoms.
ATTRV30M amyloidosis is a lethal autosomal dominant sensorimotor and autonomic neuropathy caused by amyloid deposition composed of aggregated misfolded TTR monomers with the V30M mutation.
Because leptomeningeal amyloidosis occurs in FAP ATTR Val30 Met as the progression of the disease, this information suggests that in addition to peripheral neuropathy, disorders of the central nervous system (CNS) should be given an attention in patients who underwent sequential liver transplantation using an explanted FAP ATTR Val30 Met patient's liver.
Distinct therapies for V30M TTR amyloidosis developed during the last decade exhibit promising results in slowing the peripheral and autonomic nervous system pathology.
Familial amyloidotic polyneuropathy (FAP) type I, the most common dominantly inherited form of amyloidosis, is caused by a Val-to-Met point mutation at position 30 (Val(30)-->Met) in the protein transthyretin.
Families with a variant transthyretin (TTR V30M)-associated familial amyloidotic polyneuropathy (FAP) exhibit genetic anticipation, with TTR V30M-amyloid depositing at an earlier age in successive generations.
Here, we present a 2.97 Å cryo electron microscopy structure of a fibril purified from the tissue of a patient with hereditary Val30Met ATTR amyloidosis.
Hereditary ATTR (ATTRm) amyloidosis (also called transthyretin-type familial amyloid polyneuropathy [ATTR-FAP]) is an autosomal-dominant, adult-onset, rare systemic disorder predominantly characterized by irreversible, progressive, and persistent peripheral nerve damage.TTR gene mutations (e.g. replacement of valine with methionine at position 30 [Val30Met (p.Val50Met)]) lead to destabilization and dissociation of TTR tetramers into variant TTR monomers, which form amyloid fibrils that deposit in peripheral nerves and various organs, giving rise to peripheral and autonomic neuropathy and several non-disease specific symptoms.Phenotypic and genetic variability and non-disease-specific symptoms often delay diagnosis and lead to misdiagnosis.
Hereditary ATTR V30Mamyloidosis is a lethal autosomal dominant sensorimotor and autonomic neuropathy caused by deposition of aberrant transthyretin (TTR).
However, the ocular manifestations of amyloid deposition progressed despite tafamidis therapy in Val30Met TTR amyloidosis, and the effects of tafamidis on meningovascular amyloidosis are unknown.
In 102 patients with hereditary ATTR amyloidosis (85 Val30Met and 17 non-Val30Met; 37 and 65 from endemic and non-endemic areas, respectively), results of motor nerve conduction studies (MNCSs) with a 2-Hz low-cut filter in the unilateral ulnar and tibial nerves were retrospectively investigated to assess whether each MNCS parameter demonstrated demyelinating features that fulfil the European Federation of Neurological Societies/Peripheral Nerve Society electrodiagnostic (EFNS/PNS EDX) criteria for CIDP.
In addition to the findings characteristic of homozygosity for ATTR Val30Met such as vitreous amyloidosis and relatively less autonomic involvements, this case had the unique findings of motor-dominant sensorimotor polyneuropathy and unusual sural nerve biopsy specimen results.
In the Non-Val30Met group no differences were found between DR and FAP patients pre-LT. TTR-amyloidosis symptoms showed no differences in FAP patients pre- and 5 years post-LT, irrespective of Val30Met status.
Nerve biopsy confirmed amyloid deposits in nerves, and molecular genetic analysis showed a mutation of the transthyretin (V30M) gene for 3 patients; the 2 other patients had acquired amyloidosis.