Neuronopathy, distal hereditary motor, type 5A(HMND5)

MedGen UID:: 1723540
•Concept ID:: C5399969
•: Disease or Syndrome

Synonyms:	DHMN VA; Distal Hereditary Motor Neuropathy Type V; Distal Spinal Muscular Atrophy V; HMND5; NEURONOPATHY, DISTAL HEREDITARY MOTOR, AUTOSOMAL DOMINANT 5

Gene (location): Gene(s) directly associated with this condition or phenotype.	GARS1 (7p14.3)

Monarch Initiative:	MONDO:0015353
OMIM®:	600794

Definition

The phenotypic spectrum of GARS1-associated axonal neuropathy ranges from GARS1 infantile-onset SMA (GARS1-iSMA) to GARS1 adolescent- or early adult-onset hereditary motor/sensory neuropathy (GARS1-HMSN). GARS1-iSMA. Age of onset ranges from the neonatal period to the toddler years. Initial manifestations are typically respiratory distress, poor feeding, and muscle weakness (distal greater than proximal). Weakness is slowly progressive, ultimately requiring mechanical ventilation and feeding via gastrostomy tube. GARS1-HMSN. Age of onset is most commonly during the second decade (range eight to 36 years). Initial manifestations are typically muscle weakness in the hands sometimes with sensory deficits. Lower limb involvement (seen in ~50% of individuals) ranges from weakness and atrophy of the extensor digitorum brevis and weakness of toe dorsiflexors to classic peroneal muscular atrophy with foot drop and a high steppage gait. [from GeneReviews]

Additional description

From MedlinePlus Genetics
The characteristic features of distal hereditary motor neuropathy, type V are weakness and wasting (atrophy) of muscles of the hand, specifically on the thumb side of the index finger and in the palm at the base of the thumb. Foot abnormalities, such as a high arch (pes cavus), are also common, and some affected individuals eventually develop problems with walking (gait disturbance). People with this disorder have normal life expectancies.

Symptoms of distal hereditary motor neuropathy, type V usually begin during adolescence, but onset varies from infancy to the mid-thirties. Cramps in the hand brought on by exposure to cold temperatures are often the initial symptom.

Distal hereditary motor neuropathy, type V is a progressive disorder that affects nerve cells in the spinal cord. It results in muscle weakness and affects movement of the hands and feet. https://medlineplus.gov/genetics/condition/distal-hereditary-motor-neuropathy-type-v

Clinical features

From HPO

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.

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Pes cavus

MedGen UID:: 675590
•Concept ID:: C0728829
•: Congenital Abnormality

An increase in height of the medial longitudinal arch of the foot that does not flatten on weight bearing (i.e., a distinctly hollow form of the sole of the foot when it is bearing weight).

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Hammertoe

MedGen UID:: 209712
•Concept ID:: C1136179
•: Anatomical Abnormality

Hyperextension of the metatarsal-phalangeal joint with hyperflexion of the proximal interphalangeal (PIP) joint.

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Upper limb muscle weakness

MedGen UID:: 305607
•Concept ID:: C1698196
•: Finding

Weakness of the muscles of the arms.

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Thenar muscle weakness

MedGen UID:: 330427
•Concept ID:: C1832276
•: Finding

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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.

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Hyperreflexia