U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

Neuronopathy, distal hereditary motor, autosomal dominant 8(HMN8; DHMN8)

MedGen UID:
373984
Concept ID:
C1838492
Disease or Syndrome
Synonyms: Autosomal dominant congenital benign spinal muscular atrophy; Distal spinal muscular atrophy, congenital nonprogressive; NEURONOPATHY, DISTAL HEREDITARY MOTOR, TYPE VIII; NEUROPATHY, DISTAL HEREDITARY MOTOR, TYPE VIII; SPINAL MUSCULAR ATROPHY, CONGENITAL BENIGN, WITH CONTRACTURES
SNOMED CT: Autosomal dominant congenital benign spinal muscular atrophy (763067000); Autosomal dominant benign distal spinal muscular atrophy (763067000); Congenital benign spinal muscular atrophy with contracture (763067000); Congenital nonprogressive spinal muscular atrophy (763067000)
Modes of inheritance:
Autosomal dominant inheritance
MedGen UID:
141047
Concept ID:
C0443147
Intellectual Product
Source: Orphanet
A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele.
 
Gene (location): TRPV4 (12q24.11)
 
Monarch Initiative: MONDO:0010839
OMIM®: 600175
Orphanet: ORPHA1216

Disease characteristics

Excerpted from the GeneReview: Autosomal Dominant TRPV4 Disorders
The autosomal dominant TRPV4 disorders (previously considered to be clinically distinct phenotypes before their molecular basis was discovered) are now grouped into neuromuscular disorders and skeletal dysplasias; however, the overlap within each group is considerable. Affected individuals typically have either neuromuscular or skeletal manifestations alone, and in only rare instances an overlap syndrome has been reported. The three autosomal dominant neuromuscular disorders (mildest to most severe) are: Charcot-Marie-Tooth disease type 2C. Scapuloperoneal spinal muscular atrophy. Congenital distal spinal muscular atrophy. The autosomal dominant neuromuscular disorders are characterized by a congenital-onset, static, or later-onset progressive peripheral neuropathy with variable combinations of laryngeal dysfunction (i.e., vocal fold paresis), respiratory dysfunction, and joint contractures. The six autosomal dominant skeletal dysplasias (mildest to most severe) are: Familial digital arthropathy-brachydactyly. Autosomal dominant brachyolmia. Spondylometaphyseal dysplasia, Kozlowski type. Spondyloepiphyseal dysplasia, Maroteaux type. Parastremmatic dysplasia. Metatropic dysplasia. The skeletal dysplasia is characterized by brachydactyly (in all 6); the five that are more severe have short stature that varies from mild to severe with progressive spinal deformity and involvement of the long bones and pelvis. In the mildest of the autosomal dominant TRPV4 disorders life span is normal; in the most severe it is shortened. Bilateral progressive sensorineural hearing loss (SNHL) can occur with both autosomal dominant neuromuscular disorders and skeletal dysplasias. [from GeneReviews]
Authors:
Brett A McCray  |  Alice Schindler  |  Julie E Hoover-Fong, et. al.   view full author information

Clinical features

From HPO
Clubfoot
MedGen UID:
3130
Concept ID:
C0009081
Congenital Abnormality
Clubfoot is a congenital limb deformity defined as fixation of the foot in cavus, adductus, varus, and equinus (i.e., inclined inwards, axially rotated outwards, and pointing downwards) with concomitant soft tissue abnormalities (Cardy et al., 2007). Clubfoot may occur in isolation or as part of a syndrome (e.g., diastrophic dysplasia, 222600). Clubfoot has been reported with deficiency of long bones and mirror-image polydactyly (Gurnett et al., 2008; Klopocki et al., 2012).
Pes planus
MedGen UID:
42034
Concept ID:
C0016202
Anatomical Abnormality
A foot where the longitudinal arch of the foot is in contact with the ground or floor when the individual is standing; or, in a patient lying supine, a foot where the arch is in contact with the surface of a flat board pressed against the sole of the foot by the examiner with a pressure similar to that expected from weight bearing; or, the height of the arch is reduced.
Knee flexion contracture
MedGen UID:
98042
Concept ID:
C0409355
Finding
A type of knee joint contracture in which the knee is in a fixed bent (flexed) configuration such that it cannot be straightened actively or passively.
Distal lower limb muscle weakness
MedGen UID:
324514
Concept ID:
C1836450
Finding
Reduced strength of the distal musculature of the legs.
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.
Kyphosis
MedGen UID:
44042
Concept ID:
C0022821
Anatomical Abnormality
Exaggerated anterior convexity of the thoracic vertebral column.
Hyperlordosis
MedGen UID:
9805
Concept ID:
C0024003
Finding
Abnormally increased curvature (anterior concavity) of the lumbar or cervical spine.
Spinal muscular atrophy
MedGen UID:
7755
Concept ID:
C0026847
Disease or Syndrome
Spinal muscular atrophy (SMA) is characterized by muscle weakness and atrophy resulting from progressive degeneration and irreversible loss of the anterior horn cells in the spinal cord (i.e., lower motor neurons) and the brain stem nuclei. The onset of weakness ranges from before birth to adulthood. The weakness is symmetric, proximal > distal, and progressive. Before the genetic basis of SMA was understood, it was classified into clinical subtypes based on maximum motor function achieved; however, it is now apparent that the phenotype of SMN1-associated SMA spans a continuum without clear delineation of subtypes. With supportive care only, poor weight gain with growth failure, restrictive lung disease, scoliosis, and joint contractures are common complications; however, newly available targeted treatment options are changing the natural history of this disease.
Scoliosis
MedGen UID:
11348
Concept ID:
C0036439
Disease or Syndrome
The presence of an abnormal lateral curvature of the spine.
Elbow flexion contracture
MedGen UID:
98367
Concept ID:
C0409338
Acquired Abnormality
An elbow contracture that limits the ability of the elbow joint to be extended (straightened), meaning that the elbow is fixed in an flexed (bent) position.
Hip contracture
MedGen UID:
140815
Concept ID:
C0409354
Acquired Abnormality
Lack of full passive range of motion (restrictions in flexion, extension, or other movements) of the hip joint resulting from structural changes of non-bony tissues, such as muscles, tendons, ligaments, joint capsules and/or skin.
Distal muscle weakness
MedGen UID:
140883
Concept ID:
C0427065
Finding
Reduced strength of the musculature of the distal extremities.
Distal lower limb amyotrophy
MedGen UID:
324515
Concept ID:
C1836451
Disease or Syndrome
Muscular atrophy of distal leg muscles.
Proximal lower limb amyotrophy
MedGen UID:
373171
Concept ID:
C1836767
Finding
Muscular atrophy affecting proximally located muscles of the legs, i.e., of the thigh.
Distal amyotrophy
MedGen UID:
338530
Concept ID:
C1848736
Disease or Syndrome
Muscular atrophy affecting muscles in the distal portions of the extremities.
Nonprogressive muscular atrophy
MedGen UID:
870177
Concept ID:
C4024611
Disease or Syndrome
Muscular atrophy that does not display a progression in severity with time.
Arthrogryposis multiplex congenita
MedGen UID:
1830310
Concept ID:
C5779613
Disease or Syndrome
Multiple congenital contractures in different body areas.
Elevated circulating creatine kinase concentration
MedGen UID:
69128
Concept ID:
C0241005
Finding
An elevation of the level of the enzyme creatine kinase (also known as creatine phosphokinase (CK; EC 2.7.3.2) in the blood. CK levels can be elevated in a number of clinical disorders such as myocardial infarction, rhabdomyolysis, and muscular dystrophy.
Decreased fetal movement
MedGen UID:
68618
Concept ID:
C0235659
Finding
An abnormal reduction in quantity or strength of fetal movements.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVNeuronopathy, distal hereditary motor, autosomal dominant 8
Follow this link to review classifications for Neuronopathy, distal hereditary motor, autosomal dominant 8 in Orphanet.

Recent clinical studies

Etiology

Irobi J, Dierick I, Jordanova A, Claeys KG, De Jonghe P, Timmerman V
Neuromolecular Med 2006;8(1-2):131-46. doi: 10.1385/nmm:8:1-2:131. PMID: 16775372

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...