Phenotypes associated with the disease Charlevoix-Saguenay spastic ataxia (OMIM:270550):
- Scanning speech (HP:0002168): An abnormal pattern of speech in which the words are as if measured or scanned; there is a pause after every syllable, and the syllables themselves are pronounced slowly. Evidence: IEA. (OMIM:270550)
- Decreased motor nerve conduction velocity (HP:0003431): A type of decreased nerve conduction velocity that affects the motor neuron. Evidence: PCS. Frequency: 8/10. (PMID:12873855)
- Impaired vibration sensation in the lower limbs (HP:0002166): A decrease in the ability to perceive vibration in the legs. Evidence: PCS. (PMID:12873855)
- Dysmetria (HP:0001310): A type of ataxia characterized by the inability to carry out movements with the correct range and motion across the plane of more than one joint related to incorrect estimation of the distances required for targeted movements. Evidence: IEA. (OMIM:270550)
- Distal amyotrophy (HP:0003693): Muscular atrophy affecting muscles in the distal portions of the extremities. Evidence: TAS. (OMIM:270550)
- Distal muscle weakness (HP:0002460): Reduced strength of the musculature of the distal extremities. Evidence: IEA. (OMIM:270550)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. (PMID:12873855)
- Spastic gait (HP:0002064): Spasticity is manifested by increased stretch reflex which is intensified with movement velocity. This results in excessive and inappropriate muscle activation which can contribute to muscle hypertonia. Spastic gait is characterized by manifestations such as muscle hypertonia, stiff knee, and circumduction of the leg. Evidence: PCS. Frequency: 13/13. (PMID:18465152)
- Ataxia (HP:0001251): Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly). Evidence: PCS. Frequency: 16/16. (PMID:18465152)
- Hyperactive patellar reflex (HP:0007083). Evidence: PCS. Frequency: 18/18. (PMID:12873855)
- Swan neck-like deformities of the fingers (HP:0006150): A swan neck deformity describes a finger with a hyperextended PIP joint and a flexed DIP joint. The most common cause for a swan neck-like deformity is a disruption of the end of the extensor tendon. Conditions that loosen the PIP joint and allow it to hyperextend, for example conditions that weaken the volar plate, can produce a swan neck deformity of the finger. One example is rheumatoid arthritis. Another cause are conditions that tighten up the small (intrinsic) muscles of the hand and fingers, for example hand trauma or nerve disorders, such as cerebral palsy, Parkinson's disease, or stroke. Evidence: IEA. (OMIM:270550)
- Pontine T2 hypointensity (HP:4000169): A darker than expected T2 signal on magnetic resonance imaging (MRI) of the pons. Evidence: PCS. Frequency: 8/8. (PMID:23497566)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: PCS. Frequency: 18/18. (PMID:12873855)
- Progressive gait ataxia (HP:0007240): A type of gait ataxia displaying progression of clinical severity. Evidence: IEA. (OMIM:270550)
- Loss of Purkinje cells in the cerebellar vermis (HP:0007001). Evidence: IEA. (OMIM:270550)
- Progressive truncal ataxia (HP:0007221). Evidence: IEA. (OMIM:270550)
- Peroneal muscle atrophy (HP:0009049): Atrophy of the peroneous muscles, peroneus longus (also known as Fibularis longus), Peroneus brevis (also known as fibularis brevis, and Peroneus tertius (also known as fibularis tertius). Evidence: PCS. Frequency: 18/18. Onset: Adult onset (HP:0003581). (PMID:12873855)
- Distal sensory impairment (HP:0002936): An abnormal reduction in sensation in the distal portions of the extremities. Evidence: TAS. (OMIM:270550)
- Decreased sensory nerve conduction velocity (HP:0003448): Reduced speed of conduction of the action potential along a sensory nerve. Evidence: PCS. (PMID:12873855)
- Intellectual disability (HP:0001249): The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence. Evidence: IEA. (OMIM:270550)
- Cerebellar vermis atrophy (HP:0006855): Wasting (atrophy) of the vermis of cerebellum. Evidence: PCS. Frequency: 22/22. (PMID:18465152;PMID:12873855)
- Hammertoe (HP:0001765): Hyperextension of the metatarsal-phalangeal joint with hyperflexion of the proximal interphalangeal (PIP) joint. Evidence: IEA. (OMIM:270550)
- Hypermyelinated retinal nerve fibers (HP:0007922): Myelinated retinal nerve fiber (MRNF) layer is a rare and mostly benign congenital anomaly in which the retinal nerve fibers anterior to the lamina cribrosa have a myelin sheath. Evidence: PCS. Frequency: 2/18. (PMID:12873855)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: IEA. (OMIM:270550)
- Decreased number of large peripheral myelinated nerve fibers (HP:0003387): A reduced number of large myelinated nerve fibers. Evidence: PCS. (PMID:12873855)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: PCS. Frequency: 2/18. (PMID:12873855)
- Babinski sign (HP:0003487): Upturning of the big toe (and sometimes fanning of the other toes) in response to stimulation of the sole of the foot. If the Babinski sign is present it can indicate damage to the corticospinal tract. Evidence: PCS. (PMID:12873855)
- Pes cavus (HP:0001761): 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). Evidence: PCS. Frequency: 8/18. (PMID:12873855)
- Spastic ataxia (HP:0002497). Evidence: TAS. (OMIM:270550)
- Urinary urgency (HP:0000012): Urge incontinence is the strong, sudden need to urinate. Evidence: PCS. Frequency: 12/18. (PMID:12873855)
- Dysarthria (HP:0001260): Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed. Evidence: PCS. Frequency: 14/18. (PMID:12873855)
- Onion bulb formation (HP:0003383): Repeated episodes of segmental demyelination and remyelination lead to the accumulation of supernumerary Schwann cells around axons, which is referred to as onion bulb formation. This finding affects peripheral nerves. Evidence: PCS. (PMID:12873855)
- Upper motor neuron dysfunction (HP:0002493): A functional anomaly of the upper motor neuron. The upper motor neurons are neurons of the primary motor cortex which project to the brainstem and spinal chord via the corticonuclear, corticobulbar and corticospinal (pyramidal) tracts. They are involved in control of voluntary movements. Dysfunction leads to weakness, impairment of fine motor movements, spasticity, hyperreflexia and abnormal pyramidal signs. Evidence: IEA. (OMIM:270550)
- Impaired smooth pursuit (HP:0007772): An impairment of the ability to track objects with the ocular smooth pursuit system, a class of rather slow eye movements that minimizes retinal target motion. Evidence: IEA. (OMIM:270550)
- Autosomal recessive inheritance (HP:0000007): 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 individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: PCS. (PMID:12873855)
- Falls (HP:0002527). Evidence: IEA. (OMIM:270550)
- Absent Achilles reflex (HP:0003438): Absence of the Achilles reflex (also known as the ankle jerk reflex), which can normally be elicited by tapping the tendon is tapped while the foot is dorsiflexed. Evidence: PCS. (PMID:12873855)
- Spasticity (HP:0001257): A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes. Evidence: PCS. (PMID:12873855)