Congenital insensitivity to pain with anhidrosis in Taiwan: a morphometric and genetic study.
Congenital insensitivity to pain with anhidrosis (CIPA) is characterized by insensitivity to pain, anhidrosis, recurrent hyperpyrexia, mild mental retardation, and self-mutilating behavior. We report 2 brothers, aged 20 and 18 years, who suffered from phenotypes of CIPA. Both brothers had a branch site mutation in intron 7 (IVS7-33 T-->A) of the neurotrophic tyrosine kinase receptor type 1 gene. The electrophysiological studies showed no significant abnormal findings in sensory evoked potentials, motor evoked potentials to transcranial magnetic stimulation, or heart rate variations; sympathetic skin responses were absent. Morphometric study of their sural nerve histopathology revealed normal myelinated fiber density, 8,082 fibers/mm2 and 5,637 fibers/mm2 (normal 6,141 +/- 421); decreased unmyelinated fiber density, 2,537 fibers/mm2 and 2,211 fibers/mm2 (normal 28,578 +/- 8,669); increased axon size, 4.41 +/- 1.59 microm and 5.33 +/- 1.48 microm (normal 3.73 +/- 1.45), and increased axon diameter (A)/myelin thickness (M) ratio (A/M), 3.47 +/- 1.42 and 2.70 +/- 1.07 (normal 2.49 +/- 0.93). Scatterplot analysis of the G ratio (axon diameter:fiber diameter) did not show consistent results in the relationship between axon size and myelin thickness. In conclusion, the neuropathy of our CIPA patients included a marked reduction of small myelinated and unmyelinated fibers and a relatively increased axon size. This is the first CIPA family encountered in Taiwan.
Guo
Yuh-Cherng
YC
Department of Neurology, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC.
Liao
Kwong-Kum
KK
Soong
Bing-Wen
BW
Tsai
Ching-Piao
CP
Niu
Dau-Ming
DM
Lee
Hsiang-Ying
HY
Lin
Kon-Ping
KP
D000293:Adolescent; D000328:Adult; D000409:Alanine / Q000235:genetics; D001369:Axons / Q000473:pathology / Q000648:ultrastructure; D004252:DNA Mutational Analysis; D004594:Electrophysiology / Q000379:methods; D009477:Hereditary Sensory and Autonomic Neuropathies / Q000235:genetics* / Q000473:pathology* / Q000503:physiopathology / Q000648:ultrastructure; D006801:Humans; D007438:Introns / Q000235:genetics; D008297:Male; D008854:Microscopy, Electron; D009154:Mutation; D009413:Nerve Fibers, Myelinated / Q000473:pathology / Q000502:physiology / Q000648:ultrastructure; D009431:Neural Conduction / Q000502:physiology; D020917:Receptor, trkA / Q000235:genetics*; D012867:Skin / Q000294:innervation / Q000503:physiopathology; D013497:Sural Nerve / Q000473:pathology / Q000503:physiopathology / Q000648:ultrastructure; D013624:Taiwan; D013912:Threonine / Q000235:genetics
D013912:Threonine; D020917:Receptor, trkA; D000409:Alanine