autosomal dominant distal hereditary motor neuronopathy 7

Autosomal Dominant Distal Hereditary Motor Neuronopathy 7 (HMND7)

Autosomal dominant distal hereditary motor neuronopathy-7 (HMND7) is a rare neurologic disorder characterized by

Autosomal dominant distal hereditary motor neuronopathy 7 (HMND7) is a neurologic disorder characterized by progressive distal muscle wasting and weakness affecting the upper and lower limbs. The clinical features of HMND7 include:

• Distal amyotrophy: Muscle atrophy, particularly in the hands and lower limbs [2].
• Distal muscle weakness: Weakness in the muscles of the hands and feet, which can lead to difficulty walking and hand grip [1].
• Pes cavus: A foot deformity characterized by a high arch or a curled toe [3].
• Upper limb muscle weakness: Weakness in the muscles of the arms and hands [4].
• Difficulty climbing stairs and standing on heels: Due to lower leg weakness [15].

These symptoms can progress slowly over time, with most patients eventually experiencing lower limb involvement and foot deformities. Sensory impairment is uncommon in HMND7.

It's worth noting that the disorder is often characterized by a length-dependent predominantly motor neuropathy, with many forms of distal hereditary motor neuropathies (dHMN) sharing similar features [14].

Based on the provided context, here are the diagnostic tests for autosomal dominant distal hereditary motor neuronopathy 7 (HMND7):

• Clinical Genetic Test offered by Intergen for conditions such as Neuronopathy, distal hereditary motor, type 7B [4].
• Molecular Genetics Tests, including Exome Sequencing with CNV Detection [7], which is a New York State Approved Test and can be accessed via PGnome Sequencing.
• Nerve conduction studies, electromyography (EMG) testing, and clinical presentation are also used to diagnose HMND7 [8].
• Genetic testing can be used to identify a potential genetic basis for the condition, inform prognosis, and clinical management [9].

It's worth noting that there are 32 tests available in the database for this condition, as mentioned in search result 2. However, the specific details of these tests are not provided.

References: [4] - Clinical Genetic Test offered by Intergen [7] - Exome Sequencing with CNV Detection [8] - Nerve conduction studies and electromyography (EMG) testing [9] - Genetic testing for HMND7

Based on the provided context, it appears that there are no approved drugs specifically for treating autosomal dominant distal hereditary motor neuronopathy 7 (HMND7). However, symptoms of HMND7 and related conditions such as Charcot-Marie-Tooth disease can be managed using multidisciplinary supportive measures involving rehabilitation.

Current Treatment Options:

• Multidisciplinary supportive measures:
  • Rehabilitation to manage muscle weakness and atrophy
  • Physical therapy to maintain mobility and prevent further decline
  • Occupational therapy to adapt daily activities and maintain independence
• No approved drugs specifically for HMND7, but some treatments may be considered off-label or based on individual case reports.

Research and Emerging Therapies:

• Research is ongoing to identify novel gene mutations and develop targeted therapies for various forms of distal hereditary motor neuropathies.
• Some studies have explored the use of experimental treatments such as gene therapy, but these are still in the early stages of development.

References:

• [5] Symptoms of SORD Deficiency are managed using multidisciplinary supportive measures involving rehabilitation, ...
• [9] Distal HMNs have been classified into seven subgroups based on mode of inheritance, age of onset, distribution of muscle weakness, and clinical progression.
• [14] Distal hereditary motor neuropathy (dHMN) is a group of rare genetic disorders characterized by progressive degeneration of motor neurons in the peripheral nervous system, leading to muscle weakness and atrophy primarily in the distal limbs.

Please note that these treatment options are based on the provided context and may not be comprehensive or up-to-date. It's essential to consult with a healthcare professional for personalized advice and guidance.

The differential diagnosis for autosomal dominant distal hereditary motor neuronopathy 7 (HMND7) includes several conditions that share similar clinical features.

Similarities with other conditions:

• Distal hereditary motor neuropathies: HMND7 is a subtype of distal hereditary motor neuropathies, which are characterized by progressive muscle weakness and wasting in the distal limbs. Other forms of distal hereditary motor neuropathies include HMND1, HMND2, and others [4].
• Amyotrophic lateral sclerosis (ALS): Juvenile forms of ALS can present with similar clinical features to HMND7, including progressive muscle weakness and wasting [13].
• Hereditary spastic paraplegia: This condition can also present with progressive muscle weakness and wasting in the distal limbs, although it typically affects the upper motor neurons rather than the lower motor neurons [12].

Key differences:

• Inheritance pattern: HMND7 is inherited in an autosomal dominant manner, whereas ALS and hereditary spastic paraplegia can be inherited in an autosomal recessive or X-linked pattern.
• Age of onset: HMND7 typically presents in adulthood, whereas juvenile forms of ALS and hereditary spastic paraplegia present in childhood or adolescence.

Diagnostic criteria:

• Clinical evaluation: A comprehensive clinical evaluation is essential to diagnose HMND7. This includes a detailed history and physical examination, as well as neurophysiological testing (e.g., electromyography) [11].
• Genetic testing: Genetic testing can confirm the diagnosis of HMND7 by identifying mutations in the DCTN1 gene [5].

References:

[4] - Distal hereditary motor neuropathies are clinically and genetically heterogeneous disorders caused by lower motor neuron dysfunction. (Source: [8]) [11] - A novel form of distal hereditary motor neuronopathy maps to chromosome 7q21-q22. (Source: [10]) [12] - The differential diagnosis of these latter arises with juvenile forms of amyotrophic lateral sclerosis, that could be caused also by variations of these genes, as well as hereditary spastic paraplegia. (Source: [13]) [13] - A recurrent WARS mutation is a novel cause of autosomal dominant distal hereditary motor neuropathy. Brain, 140 (2017), pp. 1252-1266. (Source: [12])