A case report of congenital hypomyelination

Abstract

A 3 year, 11 month-old Japanese male with congenital hypomyelination is described. Clinical features are delay of motor development, generalized muscle hypotonia and weakness, absent tendon reflexes due to peripheral neuropathy, and normal mental development. Electrophysiologically, nerve conduction velocities could not be measured. Histological examination of the right sural nerve revealed total of absence myelin of most of the myelinated fibers. Electronmicroscopically, there was a concentric network of lamellae formed by double-layered sheets of basement membranes with fragments of Schwann cell cytoplasm around the myelinated fibers, so called "onion-bulbs". These peculiar features were similar to those in the cases reported by Lyon, (1969); Kennedy et al., (1977); Karch et al., (1975); and Anderson et al. (1973).

Congenital Amyelinating Neuropathy: A Neuropathology Case Report and Review of Prior Cases

“…Absence of myelin sheaths of intramuscular nerves was found in the trichrome stain. Myosin ATPase reaction stains revealed a deficiency of type 1 fibers and predominantly type 2A and 2B muscle fibers [5]. In 1986, Seitz reported a hypomyelination neuropathy in a female newborn where histology of muscles showed marked variation of the muscle fiber diameters with a range between 3 and 15 micrometers [6], which is similar with our case's muscle findings.…”

Dejerine–Sottas syndrome grown to maturity: overview of genetic and morphological heterogeneity and follow‐up of 25 patients*

“…Also, one of the index cases of the HMSN type III concept of Dyck probably falls in this category (Dyck & Gomez, 1968). Several cases with a similar pathology have been described subsequently (Anderson et al 1973;Joosten et al 1974;Kasman et al 1976;Koto et al 1978;Moss et al 1979;Ulrich et al 1981;Guzzetta et al 1982;Ono et al 1982;Pagès et al 1983;Tachi et al 1984;Harati & Butler, 1985;Lütschg et al 1985;Vital et al 1987;Ouvrier et al 1990;Routon et al 1991;Boylan et al 1992;Gabreëls-Festen et al 1994;Nara et al 1995;Sawaishi et al 1995;Bornemann et al 1996;Tyson et al 1997;Phillips et al 1999;Pomerance et al 2000). Most cases occurred sporadically; in a number of cases clear evidence of AR inheritance was present.…”

Heterogeneity of Congenital Motor and Sensory Neuropathies

“…There was a severe but not eomplete hypomyelination. Atypieal onion bulb formations eonsisting in double layered basement membranes and a marked amount of endoneural interstitium were found (Lyon 1969, Anderson et al 1973, Joosten et al 1974, Kennedy et al 1977, To"lighi et al 1981, Ulrich et al 1981, Guzzetta et al 1982, Ono et al 1982. As shown in the exam-pIe of the two brothers (patient 2 and 3) the histological picture seems to be so far age dependent as there was a greater number of onion bulb formations in the biopsy of the older brother.…”