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Neuropathy, hereditary sensory and autonomic, type 2A(HSAN2A)

MedGen UID:
416701
Concept ID:
C2752089
Disease or Syndrome
Synonyms: ACROOSTEOLYSIS, GIACCAI TYPE; ACROOSTEOLYSIS, NEUROGENIC; Hereditary sensory and autonomic neuropathy type IIA; HSAN IIA; HSAN2A; NEUROPATHY, HEREDITARY SENSORY RADICULAR, AUTOSOMAL RECESSIVE; NEUROPATHY, HEREDITARY SENSORY, TYPE IIA
SNOMED CT: Hereditary sensory autonomic neuropathy type IIA (860809000)
 
Genes (locations): KIF1A (2q37.3); RETREG1 (5p15.1); SCN9A (2q24.3); WNK1 (12p13.33)
 
Monarch Initiative: MONDO:0024309
OMIM®: 201300

Disease characteristics

Hereditary sensory and autonomic neuropathy type II (HSAN2) is characterized by progressively reduced sensation to pain, temperature, and touch. Onset can be at birth and is often before puberty. The sensory deficit is predominantly distal with the lower limbs more severely affected than the upper limbs. Over time sensory function becomes severely reduced. Unnoticed injuries and neuropathic skin promote ulcerations and infections that result in spontaneous amputation of digits or the need for surgical amputation. Osteomyelitis is common. Painless fractures can complicate the disease. Autonomic disturbances are variable and can include hyperhidrosis, tonic pupils, and urinary incontinence in those with more advanced disease. [from GeneReviews]
Authors:
Ingo Kurth   view full author information

Additional description

From MedlinePlus Genetics
The effects of HSAN2 on the autonomic nervous system are more variable. Some infants with HSAN2 have digestive problems such as the backflow of stomach acids into the esophagus (gastroesophageal reflux) or slow eye-blink or gag reflexes. Affected individuals may also have weak deep-tendon reflexes, such as the reflex being tested when a doctor taps the knee with a hammer.

The signs and symptoms of HSAN2 typically begin in infancy or early childhood. The first sign of the condition is usually numbness in the hands and feet. Soon after, affected individuals lose the ability to feel pain or sense hot and cold. In people with HSAN2, unnoticed injuries often lead to open sores (ulcers) on the hands and feet. Because affected individuals cannot feel the pain of these sores, they may not seek treatment right away. Without treatment, the ulcers can become infected and may require amputation of the affected area. People with HSAN2 often injure themselves unintentionally, typically by biting the tongue, lips, or fingers. These injuries may lead to loss of the affected areas, such as the tip of the tongue. Affected individuals often have injuries and fractures in their hands, feet, limbs, and joints that go untreated because of the inability to feel pain. Repeated injury can lead to a condition called Charcot joints, in which the bones and tissue surrounding joints are damaged.

Some people with HSAN2 lose a type of taste bud on the tip of the tongue called lingual fungiform papillae and have a diminished sense of taste.

Hereditary sensory and autonomic neuropathy type II (HSAN2) is a condition that primarily affects the sensory nerve cells (sensory neurons), which transmit information about sensations such as pain, temperature, and touch to the brain. These sensations are impaired in people with HSAN2. In some affected people, the condition may also cause mild abnormalities of the autonomic neurons, which control involuntary body functions such as heart rate, digestion, and breathing. The sensory and autonomic neurons are part of the body's peripheral nervous system, which comprises the nerves outside the brain and spinal cord. HSAN2 is considered a form of peripheral neuropathy.  https://medlineplus.gov/genetics/condition/hereditary-sensory-and-autonomic-neuropathy-type-ii

Clinical features

From HPO
Acroosteolysis
MedGen UID:
183017
Concept ID:
C0917990
Disease or Syndrome
Dissolution or degeneration of bone tissue of the phalanges of the hand.
Autoamputation of digits
MedGen UID:
343770
Concept ID:
C1852289
Finding
The spontaneous detachment of a digit (finger or toe) from the body due to long standing pathology.
Foot acroosteolysis
MedGen UID:
871259
Concept ID:
C4025744
Pathologic Function
Feeding difficulties in infancy
MedGen UID:
436211
Concept ID:
C2674608
Finding
Impaired feeding performance of an infant as manifested by difficulties such as weak and ineffective sucking, brief bursts of sucking, and falling asleep during sucking. There may be difficulties with chewing or maintaining attention.
Gastroesophageal reflux
MedGen UID:
1368658
Concept ID:
C4317146
Finding
A condition in which the stomach contents leak backwards from the stomach into the esophagus through the lower esophageal sphincter.
Peripheral neuropathy
MedGen UID:
18386
Concept ID:
C0031117
Disease or Syndrome
Peripheral neuropathy is a general term for any disorder of the peripheral nervous system. The main clinical features used to classify peripheral neuropathy are distribution, type (mainly demyelinating versus mainly axonal), duration, and course.
Areflexia
MedGen UID:
115943
Concept ID:
C0234146
Finding
Absence of neurologic reflexes such as the knee-jerk reaction.
Hyporeflexia
MedGen UID:
195967
Concept ID:
C0700078
Finding
Reduction of neurologic reflexes such as the knee-jerk reaction.
Painless fractures due to injury
MedGen UID:
325208
Concept ID:
C1837602
Finding
An increased tendency to fractures following trauma, with fractures occurring without pain.
Decreased sensory nerve conduction velocity
MedGen UID:
336512
Concept ID:
C1849148
Finding
Reduced speed of conduction of the action potential along a sensory nerve.
Decreased nerve conduction velocity
MedGen UID:
347509
Concept ID:
C1857640
Finding
A reduction in the speed at which electrical signals propagate along the axon of a neuron.
Decreased number of peripheral myelinated nerve fibers
MedGen UID:
346872
Concept ID:
C1858285
Finding
A loss of myelinated nerve fibers in the peripheral nervous system (in general, this finding can be observed on nerve biopsy).
Hypotonia
MedGen UID:
10133
Concept ID:
C0026827
Finding
Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.
Generalized hypotonia
MedGen UID:
346841
Concept ID:
C1858120
Finding
Generalized muscular hypotonia (abnormally low muscle tone).
Abnormality of metabolism/homeostasis
MedGen UID:
867398
Concept ID:
C4021768
Finding
Hypogeusia
MedGen UID:
57498
Concept ID:
C0151934
Finding
A decreased ability to perceive flavor.
Anhidrosis
MedGen UID:
1550
Concept ID:
C0003028
Disease or Syndrome
Inability to sweat.
Paronychia
MedGen UID:
45334
Concept ID:
C0030578
Disease or Syndrome
The nail disease paronychia is an often-tender bacterial or fungal hand infection or foot infection where the nail and skin meet at the side or the base of a finger or toenail. The infection can start suddenly (acute paronychia) or gradually (chronic paronychia).
Episodic hyperhidrosis
MedGen UID:
387757
Concept ID:
C1857171
Finding
Intermittent episodes of abnormally increased perspiration.
Acral ulceration
MedGen UID:
1648438
Concept ID:
C4732740
Finding
A type of digital ulcer that manifests as an open sore on the surface of the skin at the tip of a finger or toe.
Decreased corneal reflex
MedGen UID:
57723
Concept ID:
C0151572
Finding
An abnormally reduced response to stimulation of the cornea (by touch, foreign body, blowing air). The corneal reflex (also known as the blink reflex, normally results in an involuntary blinking of the eyelids.

Term Hierarchy

Recent clinical studies

Diagnosis

Yuan JH, Cheng X, Matsuura E, Higuchi Y, Ando M, Hashiguchi A, Yoshimura A, Nakachi R, Mine J, Taketani T, Maeda K, Kawakami S, Kira R, Tanaka S, Kanai K, Dib-Hajj F, Dib-Hajj SD, Waxman SG, Takashima H
J Peripher Nerv Syst 2023 Dec;28(4):597-607. Epub 2023 Aug 18 doi: 10.1111/jns.12590. PMID: 37555797

Prognosis

Pareyson D, Saveri P, Sagnelli A, Piscosquito G
Neurosci Lett 2015 Jun 2;596:66-77. Epub 2015 Apr 3 doi: 10.1016/j.neulet.2015.04.001. PMID: 25847151

Clinical prediction guides

Yuan JH, Cheng X, Matsuura E, Higuchi Y, Ando M, Hashiguchi A, Yoshimura A, Nakachi R, Mine J, Taketani T, Maeda K, Kawakami S, Kira R, Tanaka S, Kanai K, Dib-Hajj F, Dib-Hajj SD, Waxman SG, Takashima H
J Peripher Nerv Syst 2023 Dec;28(4):597-607. Epub 2023 Aug 18 doi: 10.1111/jns.12590. PMID: 37555797

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