Members of a kinship with recessive hereditary sensory neuropathy (HSN-type II) and a person from another kinship with the dominant hereditary variety (HSN-type I) were investigated with quantitative studies of cutaneous touch-pressure, temperature discrimination, and pricking pain sensations, in vitro study of compound action potential and histologic studies of sural nerve biopsy specimens, and analysis of lipids of open liver biopsy specimens. In contrast to the type I disorder, the type II disorder is already present at birth or shortly thereafter, sensation is abnormal more diffusely over the body, touch-pressure sensation is affected more than pain and temperature sensations, and myelinated fibers are more affected than unmyelinated fibers. No lipid abnormality was found.
Michiya Ohta, Ralph D. Ellefson, Edward H. Lambert, Peter James Dyck. Hereditary Sensory Neuropathy, Type IIClinical, Electrophysiologic, Histologic, and Biochemical Studies of a Quebec Kinship. Arch Neurol. 1973;29(1):23–37. doi:10.1001/archneur.1973.00490250041005