SNOMEDCT: 763460007;
Iwashita et al. (1969, 1970) reported a Korean brother and sister with optic atrophy, hearing loss, and distal neurogenic atrophy. The older brother, who was more severely affected, was noted to have a peculiar hand posture at age 8 years. Both hands showed ulnar deviation and flexed fingers. At age 13, he developed progressive hearing and visual loss with optic atrophy, and began to have difficulty walking. Physical examination at age 25 years showed thoracic scoliosis, funnel chest, and a short right thumb. There were no foot deformities. He had marked distal muscle atrophy, more pronounced in the upper limbs. Sensory loss of all modalities was restricted to the lower limbs. He had an ataxic, broad-based gait. Nerve conduction velocities were normal and sural nerve biopsy showed slight demyelination. The sister had distal weakness and atrophy of the upper limbs with the same hand deformity as her brother, but no weakness or atrophy of the lower limbs. She had mild hearing loss and optic atrophy without visual impairment. Other features included slight thoracic scoliosis and brachytelephalangia of the right thumb. She had no sensory impairment.
Iwashita et al. (1970) suggested that inheritance of the disorder in the family they described was autosomal recessive, thus excluding the disorder described by Rosenberg and Chutorian (1967), which showed X-linked inheritance (CMTX5; 311070). Konigsmark and Gorlin (1976) considered them to be separate disorders.
See 165199 for a possible autosomal dominant form of the disorder.
Iwashita, H., Inoue, N., Araki, S., Kuriowa, Y. Optic atrophy, neural deafness, and distal neurogenic amyotrophy: report of a family with two affected siblings. Arch. Neurol. 22: 357-364, 1970. [PubMed: 5417642] [Full Text: https://doi.org/10.1001/archneur.1970.00480220071010]
Iwashita, H., Inoue, N., Kuroiwa, Y. Familial optic and acoustic nerve degeneration with distal amyotrophy. Lancet 294: 219-220, 1969. Note: Originally Volume 2. [PubMed: 4183781] [Full Text: https://doi.org/10.1016/s0140-6736(69)91462-7]
Konigsmark, B. W., Gorlin, R. J. Genetic and Metabolic Deafness. Philadelphia: W. B. Saunders (pub.) 1976. Pp. 108-110.
Rosenberg, R. N., Chutorian, A. Familial opticoacoustic nerve degeneration and polyneuropathy. Neurology 17: 827-832, 1967. [PubMed: 6069085] [Full Text: https://doi.org/10.1212/wnl.17.9.827]