Hereditary sensory and autonomic neuropathy

For the gene HSN2, see HSN2.

Not to be confused with Hereditary motor and sensory neuropathy.

Hereditary sensory and autonomic neuropathy
Classification and external resources
ICD-9	356.2
OMIM	162400 201300 223900 256800 608654
DiseasesDB	32501 32096 11631 32097 32610
MeSH	D009477

Hereditary sensory and autonomic neuropathy (HSAN) or hereditary sensory neuropathy (HSN) is a condition used to describe any of the types of this disease^[1] which inhibit sensation.

They are less common than Charcot-Marie-Tooth disease.^[2]

Classification

Five different clinical entities have been described under hereditary sensory and autonomic neuropathies – all characterized by progressive loss of function that predominantly affects the peripheral sensory nerves. Their incidence has been estimated to be about 1 in 25,000.

Type 1

Type 1 is the most common of the hereditary sensory and autonomic neuropathies (HSAN). Current names are: hereditary sensory neuropathy type I (HSN I), hereditary sensory and autonomic neuropathy type I (HSAN I).^[3] Historical names include: Hereditary sensory radicular neuropathy, ulcero-mutilating neuropathy, thevenard syndrome, familial trophoneurosis, mal perforant du pied, and familial syringomyelia.^[3] Sub-type 1C is also currently known as Charcot-Marie-Tooth type 2B syndrome (HMSN 2B).^[3]

Type 1 is transmitted as autosomal dominant trait and is characterized by a sensory deficit in the distal portion of the lower extremities, chronic perforating ulcerations of the feet and progressive destruction of underlying bones. Sweating abnormalities occur but other autonomic features are not found in this type. Symptoms appear in late childhood on early adolescence with trophic ulcers as pain sensation is affected more. Many patients have accompanying nerve deafness and atrophy of the peroneal muscles. Histopathologic examination reveals a marked reduction in the number of unmyelinated fibers. Motor nerve conduction velocities are normal, but the sensory nerve action potentials are absent.

Type 2, Congenital sensory neuropathy

Type 2, congenital sensory neuropathy (also historically known as Morvan's disease^[4]), is characterized by onset of symptoms in early infancy or childhood. Upper & lower extremities are affected with chronic ulcerations and multiple injuries to fingers and feet. Pain sensation is affected predominantly and deep tendon reflexes are reduced. Autoamputation of the distal phalanges is common and so is neuropathic joint degeneration. The NCV shows reduced or absent sensory nerve action potentials and nerve biopsy shows total loss of myelinated fibers and reduced numbers of unmyelinated fibers. It is inherited as an autosomal recessive condition.

Type 3, Familial dysautonomia

Main article: Familial dysautonomia

Type 3, familial dysautonomia (FD) or Riley-Day syndrome, is an autosomal recessive disorder seen predominantly in Jews of eastern European descent. Patients present with sensory and autonomic disturbances. Newborns have absent or weak suck reflex, hypotonia and hypothermia. Retarded physical development, poor temperature and motor in coordination are seen in early childhood. Other features include reduced or absent tears, depressed deep tendon reflexes, absent corneal reflex, postural hypotension and relative indifference to pain. Scoliosis is frequent. Intelligence remains normal. Many patients die in infancy and childhood. Lack of flare with intradermal histamine is seen. Histopathology of peripheral nerve shows reduced number of myelinated and non-myelinated axons. The catecholamine endings are absent.

Type 4, Congenital insensitivity to pain with anhidrosis

Main article: Congenital insensitivity to pain with anhidrosis

Type 4, congenital insensitivity to pain with anhidrosis (CIPA), is an autosomal recessive condition and affected infants present with episodes of hyperthermia unrelated to environmental temperature, anhidrosis and insensitivity to pain. Palmar skin is thickened and charcot joints are commonly present. NCV shows motor and sensory nerve action potentials to be normal. The histopathology of peripheral nerve biopsy reveals absent small unmyelinated fibers and mitochondria are abnormally enlarged.

Type 5, Congenital insensitivity to pain with partial anhidrosis

Type 5, congenital insensitivity to pain with partial anhidrosis,^[4] also manifests with congenital insensitivity to pain & anhidrosis. There is a selective absence of small myelinated fibers differentiating it from Type IV (CIPA).

Associated genes

Type	Sub-type	Gene	Locus
HSAN 1	1A	SPTLC1[5]	9q22.1-q22.3
	1B	unknown (OMIM 608088)[3]	3p24–p22
	1C (= CMT2B, HMSN IIB)	RAB7A[3]	3q21
	1D	unknown[3]	unknown
HSAN 2		HSN2[6]	12p13.33
HSAN 3 (Familial dysautonomia)		IKBKAP	9q31
HSAN 4 (CIPA)		NTRK1	1q21-q22
HSAN5		NGFß[7][8]	1p13.1
		NTRK1[9]

External links

• GeneReviews/NIH/NCBI/UW entry on Hereditary Sensory and Autonomic Neuropathy IV
• GeneReviews/NIH/NCBI/UW entry on Hereditary Sensory Neuropathy Type I
• GeneReviews/NIH/NCBI/UW entry on Hereditary Sensory and Autonomic Neuropathy Type II

References

1. ^ "eMedicine - Autonomic Neuropathy : Article by Cory Toth". http://www.emedicine.com/NEURO/topic720.htm. 
2. ^ Houlden H, Blake J, Reilly MM (October 2004). "Hereditary sensory neuropathies". Curr. Opin. Neurol. 17 (5): 569–77. doi:10.1097/00019052-200410000-00007. PMID 15367861. http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?issn=1350-7540&volume=17&issue=5&spage=569. 
3. ^ ^{a b c d e f} Michaela Auer-Grumbach (March 2008). "Hereditary sensory neuropathy type I". Orphanet Journal of Rare Diseases 3 (7): 7. doi:10.1186/1750-1172-3-7. PMC 2311280. PMID 18348718. http://www.ojrd.com/content/3/1/7. Retrieved 2008-11-05. 
4. ^ ^{a b} Felicia B Axelrod and Gabrielle Gold-von Simson (October 3, 2007). "Hereditary sensory and autonomic neuropathies: types II, III, and IV". Orphanet Journal of Rare Diseases 2 (39): 39. doi:10.1186/1750-1172-2-39. PMC 2098750. PMID 17915006. http://www.ojrd.com/content/2/1/39. Retrieved 2008-11-04. 
5. ^ Houlden H, King R, Blake J, et al. (February 2006). "Clinical, pathological and genetic characterization of hereditary sensory and autonomic neuropathy type 1 (HSAN I)". Brain 129 (Pt 2): 411–25. doi:10.1093/brain/awh712. PMID 16364956. http://brain.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=16364956. 
6. ^ Lafreniere RG, MacDonald ML, Dube MP, et al. (May 2004). "Identification of a novel gene (HSN2) causing hereditary sensory and autonomic neuropathy type II through the Study of Canadian Genetic Isolates". Am. J. Hum. Genet. 74 (5): 1064–73. doi:10.1086/420795. PMC 1181970. PMID 15060842. http://linkinghub.elsevier.com/retrieve/pii/S0002-9297(07)64371-7. 
7. ^ Einarsdottir E, Carlsson A, Minde J, et al. (February 19, 2004). "A mutation in the nerve growth factor beta gene (NGFB) causes loss of pain perception". Hum. Mol. Genet. 13 (8): 799–805. doi:10.1093/hmg/ddh096. PMID 14976160. http://hmg.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=14976160. Retrieved 2008-11-04. 
8. ^ Minde J, Toolanen G, Andersson T, et al. (December 2004). "Familial insensitivity to pain (HSAN V) and a mutation in the NGFB gene. A neurophysiological and pathological study". Muscle Nerve 30 (6): 752–760. doi:10.1002/mus.20172. PMID 15468048. 
9. ^ Henry Houlden, R. H. M. King, A. Hashemi-Nejad, et al. (April 2001). "A novel TRK A (NTRK1) mutation associated with hereditary sensory and autonomic neuropathy type V". Annals of Neurology 49 (4): 521–525. doi:10.1002/ana.103. PMID 11310631.