Table 3.

Classification of the hereditary sensory and autonomic neuropathies

Type	Inheritance	Gene/locus	Specific phenotype
HSAN I (HSN1)	AD	SPTLC1	Mainly sensory, sensory complications, motor involvement variable, neuropathic pain
CMT2B	AD	RAB7	Sensorimotor, sensory complications, no pain
HSAN 1B	AD	3p22-p24	Sensory, cough, gastroesophageal reflux
HSAN II	AR	HSN2	Severe sensory complications, mutilations, onset first two decades
HSAN III	AR	IKBKAP	Familial dysautonomia or Riley-Day syndrome, prominent autonomic, absence fungiform papillae of the tongue
HSAN IV	AR	NTRK1	Congenital insensitivity to pain with anhydrosis (CIPA), severe sensory, anhydrosis, mental retardation, unmyelintated fibers mainly affected
HSAN V	AR	NTRK1	Congenital insensitivity to pain with mild anhydrosis, no mental retardation, small myelinated fibers mainly affected
HSAN V	AR	NGFB	Congenital insensitivity to pain, minimal autonomic, no mental retardation, mainly unmyelinated fibers affected
Channelopathy	AR	SCN9A	Congenital insensitivity to pain. Associated insensitivity to pain

SPLTC1 = serine palmitoyltransferase, long-chain base subunit-1; HSN2 = hereditary sensory neuropathy type II gene; IKBKAP = inhibitor of kappa light polypeptide gene enhancer in B-cells, kinase complex-associated protein; NTRK1 = neurotrophic tyrosine kinase receptor type 1; NGFB = nerve growth factor beta polypeptide; SCN9A = sodium channel, voltagegated, type IX, alpha subunit