title: A case of familial amyloid polyneuropathy (FAP ATTR Ile107Val) with proximal muscle weakness in the lower extremities.
abstract: Proximal dominant muscle weakness is rare in transthyretin (TTR)-related familial amyloid polyneuropathy (FAP). A 69-year-old Japanese man developed numbness and dysesthesia of the first, second and third digits of both hands since 2008. He presented to our hospital with one year history of progressive proximal muscle weakness in the lower extremities since 2013. Neurological examinations revealed predominant proximal muscle weakness and atrophy with areflexia in the lower extremities, decreased superficial sensation in the first, second and third fingers of both hands, and decreased superficial and deep sensation in the lower extremities. Nerve conduction studies revealed an axonal degeneration type of sensorimotor polyneuropathy and bilateral carpal tunnel syndrome. Electromyogram revealed acute and chronic neurogenic changes predominantly in proximal muscles. We performed biopsy of the left quadriceps muscle and observed neurogenic changes in the muscle tissue and an amyloid deposition in the adipose tissue. This amyloid deposition was not seen in endomysium, perimysium and blood vessels. Genetic analysis of the TTR gene revealed the patient was heterozygous for a single nucleotide substitution c.379 A>G, which resulted in the replacement of valine with isoleucine at position 107 of the mature protein. We diagnosed his condition as FAP with Amyloid Transthyretin (ATTR) Ile107Val.
authors.affiliation: Department of Neurology, Chikamori Hospital.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kuzume
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Sajima
authors.forename: Yuko
authors.initials: Y
authors.lastname: Morimoto
authors.forename: Kanako
authors.initials: K
authors.lastname: Komatsu
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamasaki
authors.forename: Hideaki
authors.initials: H
authors.lastname: Enzan
mesh_terms: D000368:Aged; D028227:Amyloid Neuropathies, Familial / Q000150:complications / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D004576:Electromyography; D006801:Humans; D007532:Isoleucine; D035002:Lower Extremity; D008297:Male; D018908:Muscle Weakness / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D009431:Neural Conduction; D009460:Neurologic Examination; D011228:Prealbumin / Q000235:genetics; D052097:Quadriceps Muscle / Q000473:pathology; D014633:Valine
chemical_list: D011228:Prealbumin; D007532:Isoleucine; D014633:Valine