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Troyer syndrome(SPG20)

MedGen UID:
97950
Concept ID:
C0393559
Disease or Syndrome
Synonyms: Autosomal recessive spastic paraplegia type 20; Spastic paraparesis childhood-onset with distal muscle wasting; Spastic paraplegia 20; Spastic paraplegia autosomal recessive Troyer type; SPG20
SNOMED CT: Troyer syndrome (230264003)
Modes of inheritance:
Autosomal recessive inheritance
MedGen UID:
141025
Concept ID:
C0441748
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 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).
 
Gene (location): SPART (13q13.3)
 
Monarch Initiative: MONDO:0010156
OMIM®: 275900
Orphanet: ORPHA101000

Disease characteristics

Excerpted from the GeneReview: Troyer Syndrome
Troyer syndrome is characterized by progressive spastic paraparesis, dysarthria, pseudobulbar palsy, distal amyotrophy, short stature, and subtle skeletal abnormalities. Most affected children exhibit delays in walking and speech and difficulty in managing oral secretions, followed by increased lower-limb spasticity and slow deterioration in both gait and speech. Mild cerebellar signs are common. The most severely affected individuals have choreoathetosis. Emotional lability / difficulty in controlling emotions and affective disorders, such as inappropriate euphoria and/or crying, are frequently described. Life expectancy is normal. [from GeneReviews]
Authors:
Emma Baple  |  Andrew Crosby   view full author information

Additional description

From MedlinePlus Genetics
People with Troyer syndrome can experience a variety of signs and symptoms. The most common characteristics of Troyer syndrome are spasticity of the leg muscles, progressive muscle weakness, paraplegia, muscle wasting in the hands and feet (distal amyotrophy), small stature, developmental delay, learning disorders, speech difficulties (dysarthria), and mood swings. Other characteristics can include exaggerated reflexes (hyperreflexia) in the lower limbs, uncontrollable movements of the limbs (choreoathetosis), skeletal abnormalities, and a bending outward (valgus) of the knees.

Troyer syndrome causes the degeneration and death of muscle cells and motor neurons (specialized nerve cells that control muscle movement) throughout a person's lifetime, leading to a slow progressive decline in muscle and nerve function. The severity of impairment related to Troyer syndrome increases as a person ages. Most affected individuals require a wheelchair by the time they are in their fifties or sixties.

Troyer syndrome is part of a group of genetic disorders known as hereditary spastic paraplegias. These disorders are characterized by progressive muscle stiffness (spasticity) and the development of paralysis of the lower limbs (paraplegia). Hereditary spastic paraplegias are divided into two types: pure and complex. The pure types involve the lower limbs. The complex types involve the lower limbs and can also affect the upper limbs to a lesser degree; the structure or functioning of the brain; and the nerves connecting the brain and spinal cord to muscles and sensory cells that detect sensations such as touch, pain, heat, and sound (the peripheral nervous system). Troyer syndrome is a complex hereditary spastic paraplegia.  https://medlineplus.gov/genetics/condition/troyer-syndrome

Clinical features

From HPO
Urinary urgency
MedGen UID:
39315
Concept ID:
C0085606
Finding
Urge incontinence is the strong, sudden need to urinate.
Brachydactyly
MedGen UID:
67454
Concept ID:
C0221357
Congenital Abnormality
Digits that appear disproportionately short compared to the hand/foot. The word brachydactyly is used here to describe a series distinct patterns of shortened digits (brachydactyly types A-E). This is the sense used here.
Ankle clonus
MedGen UID:
68672
Concept ID:
C0238651
Finding
Clonus is an involuntary tendon reflex that causes repeated flexion and extension of the foot. Ankle clonus is tested by rapidly flexing the foot upward.
Ulnar deviation of the hand
MedGen UID:
66031
Concept ID:
C0241521
Finding
Divergence of the longitudinal axis of the hand at the wrist in a posterior (ulnar) direction (i.e., towards the little finger).
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).
Hammertoe
MedGen UID:
209712
Concept ID:
C1136179
Anatomical Abnormality
Hyperextension of the metatarsal-phalangeal joint with hyperflexion of the proximal interphalangeal (PIP) joint.
Lower limb muscle weakness
MedGen UID:
324478
Concept ID:
C1836296
Finding
Weakness of the muscles of the legs.
Short foot
MedGen UID:
376415
Concept ID:
C1848673
Finding
A measured foot length that is more than 2 SD below the mean for a newborn of 27 - 41 weeks gestation, or foot that is less than the 3rd centile for individuals from birth to 16 years of age (objective). Alternatively, a foot that appears disproportionately short (subjective).
Clinodactyly
MedGen UID:
1644094
Concept ID:
C4551485
Congenital Abnormality
An angulation of a digit at an interphalangeal joint in the plane of the palm (finger) or sole (toe).
Short stature
MedGen UID:
87607
Concept ID:
C0349588
Finding
A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms).
Dysphagia
MedGen UID:
41440
Concept ID:
C0011168
Disease or Syndrome
Difficulty in swallowing.
Chronic constipation
MedGen UID:
98325
Concept ID:
C0401149
Sign or Symptom
Constipation for longer than three months with fewer than 3 bowel movements per week, straining, lumpy or hard stools, and a sensation of anorectal obstruction or incomplete defecation.
Dysarthria
MedGen UID:
8510
Concept ID:
C0013362
Mental or Behavioral Dysfunction
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.
Intellectual disability, mild
MedGen UID:
10044
Concept ID:
C0026106
Mental or Behavioral Dysfunction
Mild intellectual disability is defined as an intelligence quotient (IQ) in the range of 50-69.
Babinski sign
MedGen UID:
19708
Concept ID:
C0034935
Finding
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.
Spastic paraparesis
MedGen UID:
52432
Concept ID:
C0037771
Sign or Symptom
Mild or moderate loss of motor function accompanied by spasticity in the lower extremities. This condition is a manifestation of CENTRAL NERVOUS SYSTEM DISEASES that cause injury to the motor cortex or descending motor pathways.
Spastic paraplegia
MedGen UID:
20882
Concept ID:
C0037772
Disease or Syndrome
Spasticity and weakness of the leg and hip muscles.
Emotional lability
MedGen UID:
39319
Concept ID:
C0085633
Mental or Behavioral Dysfunction
Unstable emotional experiences and frequent mood changes; emotions that are easily aroused, intense, and/or disproportionate to events and circumstances.
Hyperreflexia
MedGen UID:
57738
Concept ID:
C0151889
Finding
Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles.
Spastic gait
MedGen UID:
115907
Concept ID:
C0231687
Finding
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.
Dysmetria
MedGen UID:
68583
Concept ID:
C0234162
Finding
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.
Knee clonus
MedGen UID:
488908
Concept ID:
C0520823
Finding
Clonus is an involuntary tendon reflex that causes repeated flexion and extension of the foot. Knee clonus can be tested by rapidly pushing the patella towards the toes.
Global developmental delay
MedGen UID:
107838
Concept ID:
C0557874
Finding
A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.
Cerebellar atrophy
MedGen UID:
196624
Concept ID:
C0740279
Disease or Syndrome
Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event.
Lower limb spasticity
MedGen UID:
220865
Concept ID:
C1271100
Finding
Spasticity (velocity-dependent increase in tonic stretch reflexes with increased muscle tone and hyperexcitable tendon reflexes) in the muscles of the lower limbs, hips, and pelvis
Upper limb spasticity
MedGen UID:
220882
Concept ID:
C1273957
Finding
Motor delay
MedGen UID:
381392
Concept ID:
C1854301
Finding
A type of Developmental delay characterized by a delay in acquiring motor skills.
Impaired vibration sensation at ankles
MedGen UID:
343107
Concept ID:
C1854372
Finding
A decrease in the ability to perceive vibration at the ankles. Clinically, this is usually tested with a tuning fork which vibrates at 128 Hz and is applied to the malleoli of the ankles.
Abnormal cerebellum morphology
MedGen UID:
400925
Concept ID:
C1866129
Anatomical Abnormality
Any structural abnormality of the cerebellum.
Difficulty walking
MedGen UID:
86319
Concept ID:
C0311394
Finding
Reduced ability to walk (ambulate).
Flexion contracture
MedGen UID:
83069
Concept ID:
C0333068
Anatomical Abnormality
A flexion contracture is a bent (flexed) joint that cannot be straightened actively or passively. It is thus a chronic loss of joint motion due to structural changes in muscle, tendons, ligaments, or skin that prevents normal movement of joints.
Kyphoscoliosis
MedGen UID:
154361
Concept ID:
C0575158
Anatomical Abnormality
An abnormal curvature of the spine in both a coronal (lateral) and sagittal (back-to-front) plane.
Camptodactyly
MedGen UID:
195780
Concept ID:
C0685409
Congenital Abnormality
The distal interphalangeal joint and/or the proximal interphalangeal joint of the fingers or toes cannot be extended to 180 degrees by either active or passive extension.
Distal amyotrophy
MedGen UID:
338530
Concept ID:
C1848736
Disease or Syndrome
Muscular atrophy affecting muscles in the distal portions of the extremities.
Hyperextensible hand joints
MedGen UID:
347323
Concept ID:
C1856877
Finding
The ability of the joints of the hand to move beyond their normal range of motion.
Drooling
MedGen UID:
8484
Concept ID:
C0013132
Finding
Habitual flow of saliva out of the mouth.
Hyperplasia of midface
MedGen UID:
451009
Concept ID:
C0240309
Anatomical Abnormality
Abnormally anterior positioning of the infraorbital and perialar regions, or increased convexity of the face, or increased nasolabial angle. The midface includes the maxilla, the cheeks, the zygomas, and the infraorbital and perialar regions of the face
Hypertelorism
MedGen UID:
9373
Concept ID:
C0020534
Finding
Although hypertelorism means an excessive distance between any paired organs (e.g., the nipples), the use of the word has come to be confined to ocular hypertelorism. Hypertelorism occurs as an isolated feature and is also a feature of many syndromes, e.g., Opitz G syndrome (see 300000), Greig cephalopolysyndactyly (175700), and Noonan syndrome (163950) (summary by Cohen et al., 1995).
Nystagmus
MedGen UID:
45166
Concept ID:
C0028738
Disease or Syndrome
Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVTroyer syndrome
Follow this link to review classifications for Troyer syndrome in Orphanet.

Recent clinical studies

Etiology

Milewska M, Byrne PC
Cell Biol Int 2015 Sep;39(9):1007-15. Epub 2015 May 8 doi: 10.1002/cbin.10472. PMID: 25821002
Milewska M, McRedmond J, Byrne PC
J Neurochem 2009 Nov;111(4):1022-30. Epub 2009 Sep 16 doi: 10.1111/j.1471-4159.2009.06382.x. PMID: 19765186
Lu J, Rashid F, Byrne PC
J Neurochem 2006 Sep;98(6):1908-19. doi: 10.1111/j.1471-4159.2006.04008.x. PMID: 16945107
Bakowska JC, Jenkins R, Pendleton J, Blackstone C
Biochem Biophys Res Commun 2005 Sep 9;334(4):1042-8. doi: 10.1016/j.bbrc.2005.06.201. PMID: 16036216
Auer-Grumbach M, Fazekas F, Radner H, Irmler A, Strasser-Fuchs S, Hartung HP
J Neurol 1999 Jul;246(7):556-61. doi: 10.1007/s004150050403. PMID: 10463356

Diagnosis

Khoshaeen A, Najafi M, Mahdavi MR, Jalali H, Mahdavi M
J Genet 2020;99 PMID: 32661208
Dardour L, Roelens F, Race V, Souche E, Holvoet M, Devriendt K
Cold Spring Harb Mol Case Stud 2017 Jul;3(4) Epub 2017 Jul 5 doi: 10.1101/mcs.a001537. PMID: 28679690Free PMC Article
Tawamie H, Wohlleber E, Uebe S, Schmäl C, Nöthen MM, Abou Jamra R
Mol Cell Probes 2015 Oct;29(5):315-8. Epub 2015 May 20 doi: 10.1016/j.mcp.2015.05.006. PMID: 26003402
Rainier S, Albers JW, Dyck PJ, Eldevik OP, Wilcock S, Richardson RJ, Fink JK
Muscle Nerve 2011 Jan;43(1):19-25. doi: 10.1002/mus.21777. PMID: 21171093
Bakowska JC, Wang H, Xin B, Sumner CJ, Blackstone C
Arch Neurol 2008 Apr;65(4):520-4. doi: 10.1001/archneur.65.4.520. PMID: 18413476Free PMC Article

Prognosis

Bizzari S, Hamzeh AR, Nair P, Mohamed M, Saif F, Aithala G, Al-Ali MT, Bastaki F
Metab Brain Dis 2017 Dec;32(6):2155-2159. Epub 2017 Sep 5 doi: 10.1007/s11011-017-0104-3. PMID: 28875386
Butler S, Helbig KL, Alcaraz W, Seaver LH, Hsieh DT, Rohena L
Am J Med Genet A 2016 Jul;170(7):1780-5. Epub 2016 Apr 26 doi: 10.1002/ajmg.a.37658. PMID: 27112432
Bakowska JC, Wang H, Xin B, Sumner CJ, Blackstone C
Arch Neurol 2008 Apr;65(4):520-4. doi: 10.1001/archneur.65.4.520. PMID: 18413476Free PMC Article

Clinical prediction guides

Bizzari S, Hamzeh AR, Nair P, Mohamed M, Saif F, Aithala G, Al-Ali MT, Bastaki F
Metab Brain Dis 2017 Dec;32(6):2155-2159. Epub 2017 Sep 5 doi: 10.1007/s11011-017-0104-3. PMID: 28875386
Butler S, Helbig KL, Alcaraz W, Seaver LH, Hsieh DT, Rohena L
Am J Med Genet A 2016 Jul;170(7):1780-5. Epub 2016 Apr 26 doi: 10.1002/ajmg.a.37658. PMID: 27112432
Manzini MC, Rajab A, Maynard TM, Mochida GH, Tan WH, Nasir R, Hill RS, Gleason D, Al Saffar M, Partlow JN, Barry BJ, Vernon M, LaMantia AS, Walsh CA
Ann Neurol 2010 Apr;67(4):516-25. doi: 10.1002/ana.21923. PMID: 20437587Free PMC Article
Rainier S, Bui M, Mark E, Thomas D, Tokarz D, Ming L, Delaney C, Richardson RJ, Albers JW, Matsunami N, Stevens J, Coon H, Leppert M, Fink JK
Am J Hum Genet 2008 Mar;82(3):780-5. Epub 2008 Feb 28 doi: 10.1016/j.ajhg.2007.12.018. PMID: 18313024Free PMC Article
Auer-Grumbach M, Fazekas F, Radner H, Irmler A, Strasser-Fuchs S, Hartung HP
J Neurol 1999 Jul;246(7):556-61. doi: 10.1007/s004150050403. PMID: 10463356

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