Amyloid transthyretin (ATTR) amyloidosis with polyneuropathy (PN) is a progressive, debilitating, systemic disease wherein transthyretin protein misfolds to form amyloid, which is deposited in the endoneurium. ATTR amyloidosis with PN is the most serious hereditary polyneuropathy of adult onset. It arises from a hereditary mutation in the TTR gene and may involve the heart as well as other organs. It is critical to identify and diagnose the disease earlier because treatments are available to help slow the progression of neuropathy. Early diagnosis is complicated, however, because presentation may vary and family history is not always known. Symptoms may be mistakenly attributed to other diseases such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), idiopathic axonal polyneuropathy, lumbar spinal stenosis, and, more rarely, diabetic neuropathy and AL amyloidosis. In endemic countries (e.g., Portugal, Japan, Sweden, Brazil), ATTR amyloidosis with PN should be suspected in any patient who has length-dependent small-fiber PN with autonomic dysfunction and a family history of ATTR amyloidosis, unexplained weight loss, heart rhythm disorders, vitreous opacities, or renal abnormalities. In nonendemic countries, the disease may present as idiopathic rapidly progressive sensory motor axonal neuropathy or atypical CIDP with any of the above symptoms or with bilateral carpal tunnel syndrome, gait disorders, or cardiac hypertrophy. Diagnosis should include DNA testing, biopsy, and amyloid typing. Patients should be followed up every 6-12 months, depending on the severity of the disease and response to therapy. This review outlines detailed recommendations to improve the diagnosis of ATTR amyloidosis with PN.

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Expert consensus recommendations to improve diagnosis of ATTR amyloidosis with polyneuropathy

Ocular Manifestations of Familial Transthyretin Amyloidosis

Purpose. This paper aims to review the morphological and functional characteristics of patients affected by familial amyloid polyneuropathy (FAP), with greater focus on type I and its progression after liver transplantation. We also analyse therapeutic options for the ophthalmic manifestations. Methods. The literature from 2002 through 2015 was reviewed, with a total of 45 articles studied, using the key terms related to amyloidosis and its therapeutic approaches. Information was collated, evaluated, critically assessed, and then summarised in its present form. Pathophysiology and Treatment. FAP results from mutation of the transthyretin gene, with Val30Met being the most frequent substitution. The symptoms are those typical of a sensorimotor autonomic neuropathy and can be halted with liver transplantation. Nowadays there are new medical therapies that delay the progression of the systemic neuropathy. However, there are still no options to avoid ocular disease. Conclusion. The main ocular manifestations in patients with FAP type I are amyloid deposition in the vitreous, dry eye, and secondary glaucoma. Despite liver transplantation, eye synthesis of amyloid persists and is associated with progressive ocular manifestations, which require continued ophthalmologic follow-up. New therapeutic strategies are therefore needed, particularly to target the ocular synthesis of the abnormal protein.

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Ocular Manifestations and Therapeutic Options in Patients with Familial Amyloid Polyneuropathy: A Systematic Review

Background: Mutations of transthyretin (TTR) cause the most common type of autosomal-dominant hereditary systemic amyloidosis, which occurs worldwide. To date, more and more mutations in the TTR gene have been reported. Some variations in the clinical presentation are often observed in patients with the same mutation or the patients in the same family. The purpose of this study was to find out the clinicopathologic and genetic features of Chinese patients with hereditary TTR amyloidosis. Methods: Clinical and necessary examination materials were collected from nine patients of eight families with hereditary TTR amyloidosis at Peking University First Hospital from January 2007 to November 2014. Sural nerve biopsies were taken for eight patients and skin biopsies were taken in the calf/upper arm for two patients, for light and electron microscopy examination. The TTR genes from the nine patients were analyzed. Results: The onset age varied from 23 to 68 years. The main manifestations were paresthesia, proximal and/or distal weakness, autonomic dysfunction, cardiomyopathy, vitreous opacity, hearing loss, and glossohypertrophia. Nerve biopsy demonstrated severe loss of myelinated fibers in seven cases and amyloid deposits in three. One patient had skin amyloid deposits which were revealed from electron microscopic examination. Genetic analysis showed six kinds of mutations of TTR gene, including Val30Met, Phe33Leu, Ala36Pro, Val30Ala, Phe33Val, and Glu42Gly in exon 2. Conclusions: Since the pathological examinations of sural nerve were negative for amyloid deposition in most patients, the screening for TTR mutations should be performed in all the adult patients, who are clinically suspected with hereditary TTR amyloidosis.

Hereditary Transthyretin Amyloidosis in Eight Chinese Families

Transthyretin-related familial amyloid polyneuropathy (TTR-FAP) is a rare hereditary disorder, characterized by a length-dependent polyneuropathy and dysfunction of various organs. Wide phenotypic heterogeneity makes early diagnosis difficult. In this study, we reviewed the clinical and electrophysiological features of four unrelated Chinese families with genetically confirmed TTR-FAP. Sequence analysis of TTR gene revealed the presence of four different mutations: Thr49Ala(p.Thr69Ala), Leu55Arg(p.Leu75Arg), Tyr116Ser(p.Tyr136Ser), and Ala36Pro(p.Ala56Pro) from six affected patients and two asymptomatic individuals. Two mutations, Thr49Ala(p.Thr69Ala) and Tyr116Ser(p.Tyr136 Ser), were detected in Chinese FAP patients for the first time. All affected patients manifested a progressive sensorimotor polyneuropathy starting in the lower limbs. The majority of the examined patients displayed cardiomyopathy and vitreous opacities. To avoid misdiagnosis, clinicians should consider screening for TTR variants in patients presenting with progressive polyneuropathy of undetermined origins.

Clinical features of familial amyloid polyneuropathy carrying transthyretin mutations in four Chinese kindreds.

To describe the characteristic ophthalmic phenotypes of a large Chinese family with familial amyloid polyneuropathy due to a missense mutation in transthyretin (TTR) (c.307 C>G). Twenty-seven individuals (12 affected, 15 unaffected) from a five-generation Chinese family underwent general medical examination and comprehensive ophthalmic examination, including best correct visual acuity, intraocular pressure measurements, Schirmer test, slitlamp examination, fundoscopy, and ocular ultrasonography. Histological examination of vitreous biopsies using Congo red staining and immunohistochemistry was performed. Cardiovascular magnetic resonance (CMR), electrocardiogram, and echocardiogram were used to evaluate cardiac amyloidosis. Electromyography was used to evaluate nerve function. All four exons of TTR were amplified by PCR, sequenced using a Bigdye terminator v3.1 cycle sequencing kit and analyzed on an ABI 3700XL Genetic Analyzer. All 12 affected individuals in the family had ocular manifestations, including severe vitreous opacities, secondary glaucoma, xerophthalmia, dyscoria, and attenuated retinal arteries. Congo red staining demonstrated amyloid deposits in the vitreous, and immunohistochemical staining confirmed the deposition of TTR proteins in the vitreous. Twelve individuals had polyneuropathy, and electromyography detected functional damage in peripheral nerves. One individual was diagnosed with cardiac amyloidosis by CMR. Direct sequencing revealed the heterozygous missense mutation in TTR (c.307 C>G p.Gly83Arg) in all 12 affected individuals. The mutation co-segregated with the disease phenotype and was absent in 100 normal controls. Vitreous opacity is very common in patients with the TTR Gly83Arg mutation; other clinical characteristics associated with the mutation include polyneuropathy and cardiac amyloidosis.

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Ophthalmic manifestations in a Chinese family with familial amyloid polyneuropathy due to a TTR Gly83Arg mutation


 对于合并多种晕厥危险因素、出现过晕厥事件，且植入植入式心脏转复除颤器（ICD）二级预防的患者，再发晕厥时的诊疗和鉴别诊断颇具挑战性。本文报道因既往反复室性心动过速合并长QT综合征植入ICD的患者再发晕厥，最终溯因为肺血栓栓塞症的1例病例，并复习相关文献，以探讨合并多种晕厥危险因素时的优化晕厥诊疗模式。.


X Cheng

Papers

Ophthalmic manifestations in a Chinese family with familial amyloid polyneuropathy due to a TTR Gly83Arg mutation

[Recurrent syncope of unknown origin after ICD implantation: a case report].