New HSN2 mutation in Japanese patient with hereditary sensory and autonomic neuropathy type 2

The authors report a Japanese patient with hereditary sensory and autonomic neuropathy type 2 (HSAN2) who has a new mutation of the HSN2 gene. The pathologic findings of the patient matched those of Canadian patients. They identified a homozygous 1134-1135 ins T mutation, resulting in a frameshift, and the subsequent premature stop codon at residue 378. These observations support the hypothesis that HSN2 is a causative gene for HSAN2.     

Hereditary sensory and autonomic neuropathy II due to novel mutation in the HSN2 gene in Mexican families

Journal of Neurology -     

A mutation in the HSN2 gene causes sensory neuropathy type II in a Lebanese family

Hereditary sensory and autonomic neuropathy (HSAN) type II is an autosomal recessive disorder clinically characterized by distal and proximal sensory loss that is caused by the reduction or absence of peripheral sensory nerves. Recently, a novel gene called HSN2 has been found to be the cause of HSAN type II in five families from Newfoundland and Quebec. Screening of this gene in an HSAN type II Lebanese family showed a 1bp deletion mutation found in a homozygous state in all affected individuals. This novel mutation supports the hypothesis that HSN2 is the causative gene for HSAN type II.     

Cutaneous innervation in hereditary sensory and autonomic neuropathy type IV

The authors investigated immunocytochemically the innervation of a skin biopsy in a rare case of hereditary sensory and autonomic neuropathy type IV. A few protein gene product 9.5-, growth-associated protein 43-, calcitonin gene-related peptide-, and substance P-immunoreactive nerve fibers were observed in the deeper regions of the dermis. Neuropeptide Y-, nitric oxide-, and vasoactive intestinal polypeptide-immunoreactive fibers were completely absent. Their observations support the hypothesis that the sensory and autonomic defects reported in hereditary sensory and autonomic neuropathy are based on profound developmental alterations of the peripheral nervous system.     

A case of hereditary sensory autonomic neuropathy type IV

Hereditary sensory autonomic neuropathy type IV (HSAN -IV), also known as congenital insensitivity to pain with anhidrosis, is a very rare condition that presents in infancy with anhidrosis, absence of pain sensation and self -mutilation. Developmental delay and mental retardation are usually present. Ultrastructural study of the peripheral nerves demonstrates loss of the unmyelinated and small myelinated fibers. We here report a 8 year -old boy with HSAN IV with typical clinical features where the diagnosis was supported by nerve biopsy findings. However, our case was unusual since mental development was normal.     

Nonprogressive type II hereditary sensory autonomic neuropathy: a homogeneous clinicopathologic entity.

Two different clinical subtypes were previously identified within hereditary sensory autonomic neuropathy (HSAN) type II: a stable congenital form and a progressive one. This paper discusses two clinicopathologic cases of nonprogressive HSAN type II with morphometric correlations. In addition, a retrospective literature search was carried out to locate other cases where an accurate histologic examination, including ultrastructural features, was available in order to relate clinical and pathologic aspects of the disease. The combined data support the individualization of this neuropathic form as a homogeneous disease, as has been suggested during the last century and underline the clinical importance of this concept for the prognosis and investigation of sensory, auditory, autonomic, and motor functions in children with sensory neuropathies.     

A case of hereditary sensory autonomic neuropathy type II with late onset]

We reported a 22-year-old man with hereditary sensory autonomic neuropathy (HSAN) type II. His initial neurological symptom at the age of 18 years was hypoesthesia on the feet and legs. In spite of late onset and absence of multilating acropathy, we diagnosed this case as HSAN type II because of an absence of sensory nerve action potentials with normal motor nerve conduction velocities and of a total loss of myelinated fibers with a decrease of unmyelinated fibers in the sural nerve. The sweating induced by iontophoretic pilocarpine stimulation was decreased on the dorsum of the foot. In addition, the morphometric analysis of sudomotor nerves around sweat glands showed a decrease of nerve terminals and unmyelinated axons. Because decrease or loss of sweating is one of the cardinal signs in HSAN type II, the quantitative sweating test and morphometric evaluation of the innervation of sweat glands are important for the proof of the autonomic signs.     

Beyond neuropathy in hereditary sensory and autonomic neuropathy type V: cognitive evaluation

Background and purpose:  Hereditary sensory and autonomic neuropathy (HSAN) type V is a very rare disorder. It is characterized by the absence of thermal and mechanical pain perception caused by decreased number of small diameter neurons in peripheral nerves. Recent genetic studies have pointed out the aetiological role of nerve growth factor beta, which is also involved in the development of the autonomic nervous system and cholinergic pathways in the brain. HSAN type V is usually reported not to cause mental retardation or cognitive decline. However, a structured assessment of the cognitive profile of these patients has never been made.
Methods and results:  We performed a throughout evaluation of four HSAN type V patients and compared their performance with 37 normal individuals. Our patients showed no cognitive deficits, not even mild ones.
Discussion and Conclusions:  Although newer mutations on this and related disorders are continuously described, their clinical characterization has been restricted to the peripheral aspects of these conditions. A broader characterization of this rare disorder may contribute to better understand the mechanisms of the nociceptive and cognitive aspects of pain.     

The evaluation of autonomic nervous function in a patient with hereditary sensory and autonomic neuropathy type IV with novel mutations of the TRKA gene

We report on a 10-year-old girl with anhidrosis and insensibility to pain, but no severe mental retardation or self-mutilation, diagnosed as hereditary sensory and autonomic neuropathy type IV (HSAN IV). Genetic analysis of her TRKA gene, which is responsible for HSAN IV, revealed two novel missense mutations in the tyrosine kinase domain. Cardiovascular autonomic nervous system function tests showed normal muscle sympathetic nerve activity associated with arterial baroreflex, reduced skin sympathetic nerve activity in the second and fifth fingers and palms, and abnormal circadian rhythm of cardiovascular autonomic nervous system. These findings have never before been reported in HSAN IV and may provide a clue to the neurological pathophysiology of this disease.     

Hereditary sensory autonomic neuropathy type II: Report of two novel mutations in the FAM134B gene

Hereditary sensory autonomic neuropathy (HSAN) type II is a rare, autosomal recessive, and early onset sensory neuropathy, characterized by severe and progressive sensation impairment, leading to ulcero‐mutilating complications. FAM134B gene, also known as RETREG1 gene, mutations have been reported to be associated to HSAN‐IIB. We report four patients from two unrelated families who developed during childhood a sensory axonal neuropathy with variable severity and pronounced nociception impairment. Complications such as recurrent ulcerations, osteomyelitis, and osteonecrosis leading to distal amputation were noticed. Dysautonomia was mild or even absent in our group of patients. Additionally, either clinical or neurophysiological motor impairment was not uncommon. Presence of upper motor neuron signs was also a distinctive feature in two related patients. After extensive workup, two novel homozygous mutations in the FAM134B gene were identified. This report expands the clinical and genetic spectrum of HSAN type II and emphasizes the phenotype variability even within the same family.     

Novel NTRK1 mutations cause hereditary sensory and autonomic neuropathy type IV: demonstration of a founder mutation in the Turkish population

Hereditary sensory and autonomic neuropathy type IV (HSAN IV), or congenital insensitivity to pain with anhidrosis, is an autosomal recessive disorder characterized by insensitivity to noxious stimuli, anhidrosis from deinnervated sweat glands, and delayed mental and motor development. Mutations in the neurotrophic tyrosine kinase receptor type 1 (NTRK1), a receptor in the neurotrophin signaling pathway phosphorylated in response to nerve growth factor, are associated with this disorder. We identified six families from Northern Central Turkey with HSAN IV. We screened the NTRK1 gene for mutations in these families. Microsatellite and single nucleotide polymorphism (SNP) markers on the Affymetrix 250K chip platform were used to determine the haplotypes for three families harboring the same mutation. Screening for mutations in the NTRK1 gene demonstrated one novel frameshift mutation, two novel nonsense mutations, and three unrelated kindreds with the same splice-site mutation. Genotyping of the three families with the identical splice-site mutation revealed that they share the same haplotype. This report broadens the spectrum of mutations in NTRK1 that cause HSAN IV and demonstrates a founder mutation in the Turkish population. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Beyhan Tüysüz and Fatih Bayrakli contributed equally to this work.     

Frequency of mutations in the genes associated with hereditary sensory and autonomic neuropathy in a UK cohort

The hereditary sensory and autonomic neuropathies (HSAN, also known as the hereditary sensory neuropathies) are a clinically and genetically heterogeneous group of disorders, characterised by a progressive sensory neuropathy often complicated by ulcers and amputations, with variable motor and autonomic involvement. To date, mutations in twelve genes have been identified as causing HSAN. To study the frequency of mutations in these genes and the associated phenotypes, we screened 140 index patients in our inherited neuropathy cohort with a clinical diagnosis of HSAN for mutations in the coding regions of SPTLC1, RAB7, WNK1/HSN2, FAM134B, NTRK1 (TRKA) and NGFB. We identified 25 index patients with mutations in six genes associated with HSAN (SPTLC1, RAB7, WNK1/HSN2, FAM134B, NTRK1 and NGFB); 20 of which appear to be pathogenic giving an overall mutation frequency of 14.3%. Mutations in the known genes for HSAN are rare suggesting that further HSAN genes are yet to be identified. The p.Cys133Trp mutation in SPTLC1 is the most common cause of HSAN in the UK population and should be screened first in all patients with sporadic or autosomal dominant HSAN.     

Autosomal recessive type II hereditary motor and sensory neuropathy with acrodystrophy

A family is described with presumed autosomal recessive inheritance in which three siblings developed a progressive neuropathy that combined limb weakness and severe distal sensory loss leading to prominent mutilating changes. Electrophysiological and nerve biopsy findings indicated an axonopathy. The disorder is therefore classifiable as type II hereditary motor and sensory neuropathy (HMSN II). The clinical features differ from those reported in previously described cases of autosomal recessive HMSN II. This disorder may therefore represent a new variant. Received: 16 April 1998 Received in revised form: 26 June 1998 Accepted: 7 July 1998     

Novel frameshift and splice site mutations in the neurotrophic tyrosine kinase receptor type 1 gene (NTRK1) associated with hereditary sensory neuropathy type IV

Congenital insensitivity to pain with anhidrosis or hereditary sensory and autonomic neuropathy type IV (HSAN IV) is the first human genetic disorder implicated in the neurotrophin signal transduction pathway. HSAN IV is characterized by absence of reaction to noxious stimuli, recurrent episodes of fever, anhidrosis, self-mutilating behavior and often mental retardation. Mutations in the neurotrophic tyrosine kinase, receptor, type 1 (NTRK1) are associated with this disorder. Here we report four homozygous mutations, two frameshift (p.Gln626fsX6 and p.Gly181fsX58), one missense (p.Arg761Trp) and one splice site (c.359+5G>T) mutation in four HSAN IV patients. The splice site mutation caused skipping of exons 2 and 3 in patient's mRNA resulting in an in-frame deletion of the second leucine-rich motif. NTRK1 mutations are only rarely reported in the European population. This report extends the spectrum of NTRK1 mutations observed in patients diagnosed with HSAN IV.     

Monozygotic twins with suspected hereditary sensory and autonomic neuropathy (HSAN) type V

We report a pair of 1-year-5-month-old female monozygotic twins with generalized loss of pain sensation, but without impairment of other sensory modalities and the diaphoretic function. Routine electrophysiological investigations revealed no abnormalities. Morphometric analysis of biopsied sural nerve showed that the number of small myelinated fibers was reduced and that of unmyelinated fibers was normal or mildly reduced. On the basis of these findings, we suspected a diagnosis of a rare disorder, HSAN type V, which has not previously been reported in Japan.     

Treatment of life-threatening self-injurious behavior secondary to hereditary sensory and autonomic neuropathy type II: a controlled case study

Although self-injurious behavior is present in all subtypes of hereditary sensory and autonomic neuropathy, the literature has not sufficiently addressed the issue of treatment of self-injury in this population. Therefore, the purpose of the current case study was to describe a method for assessing and treating self-injurious behavior associated with hereditary sensory and autonomic neuropathies. This study was conducted with an 11-year-old boy diagnosed with hereditary sensory and autonomic neuropathy type II admitted to an inpatient behavioral unit over a 4-month period. A simplified version of a habit reversal treatment was used, consisting of awareness training, self-monitoring, competing responses, and social support. Treatment resulted in a 98% reduction in the rate of self-injurious behavior relative to pretreatment baseline rates. This case study illustrates that behavioral interventions may be a viable option for treating self-injury secondary to hereditary sensory and autonomic neuropathies.