Autosomal recessive spastic paraplegia type 55

General Information (adopted from Orphanet):

Synonyms, Signs: SPG55
Number of Symptoms 36
OrphanetNr: 320375
OMIM Id: 615035
ICD-10: G11.4
UMLs:
MeSH:
MedDRA:
Snomed:

Prevalence, inheritance and age of onset:

Prevalence: No data available.
Inheritance: Monogenic
Autosomal recessive
23188110 [IBIS]
Age of onset: Childhood
23188110 [IBIS]

Disease classification (adopted from Orphanet):

Parent Diseases: Autosomal recessive complex spastic paraplegia
 -Rare genetic disease
 -Rare neurologic disease
Mitochondrial disorder due to a defect in mitochondrial protein synthesis
 -Rare developmental defect during embryogenesis
 -Rare genetic disease
 -Rare neurologic disease

Comment:

Hereditary spastic paraplegias (HSPs) comprise a large and heterogeneous group of genetic disorders mainly affecting the pyramidal tracts of the legs. The cardinal pathological findings in HSPs are the result of a dying back degeneration of the corticospinal tracts in the spinal cord. The longest fibres, innervating the lower extremities are mostly affected. HSPs are divided into two subtypes that comprise pure and complex forms. HSPs can be inherited in an autosomal-dominant (AD), autosomal-recessive (AR) or X-linked recessive (XR) manner. The pure form is usually transmitted as an AD trait, whereas the complex form is transmitted as an AR or XR one. An autosomal-recessive homozygous nonsense mutation (c.394C>T, p.R132X) of C12orf65 (= SPG55; COXPD7) causes spastic paraplegia with optic atrophy and neuropathy (SPG55). In COXPD7 patients the cardinal clinical feature is Leigh syndrom. Their fibroblasts have been reported to exhibit severe decreases in complexes I, IV and V. Meanwhile, SPG55 patient ’s fibroblasts showed decreases in complexes I and IV, and a milder decrease in complex V. Their cardinal clinical feature is spastic paraplegia (PMID:23188110).

Symptom Information: Sort by abundance 

1
 (HPO:0000648) Optic atrophy Very frequent [IBIS] 23188110 IBIS 238 / 7739
2
 (HPO:0000546) Retinal degeneration 23188110 IBIS 61 / 7739
3
 (HPO:0000602) Ophthalmoplegia 20598281 IBIS 56 / 7739
4
 (HPO:0000575) Scotoma 23188110 IBIS 11 / 7739
5
 (HPO:0000603) Central scotoma 23188110 IBIS 18 / 7739
6
 (HPO:0000505) Visual impairment 23188110 IBIS 297 / 7739
7
 (HPO:0007663) Reduced visual acuity rare [HPO:skoehler] 23188110 IBIS 100 / 7739
8
 (HPO:0008972) Decreased activity of mitochondrial respiratory chain 23188110 IBIS 34 / 7739
9
 (HPO:0011925) Decreased activity of mitochondrial ATP synthase complex 23188110 IBIS 10 / 7739
10
 (HPO:0011923) Decreased activity of mitochondrial complex I 23188110 IBIS 35 / 7739
11
 (HPO:0008347) Decreased activity of mitochondrial complex IV 23188110 IBIS 31 / 7739
12
 (HPO:0003202) Skeletal muscle atrophy 23188110 IBIS 281 / 7739
13
 (HPO:0003457) EMG abnormality 23188110 IBIS 78 / 7739
14
 (HPO:0002355) Difficulty walking 23188110 IBIS 61 / 7739
15
 (HPO:0002169) Clonus 23188110 IBIS 37 / 7739
16
 (HPO:0011449) Knee clonus 23188110 IBIS 10 / 7739
17
 (HPO:0009063) Progressive distal muscle weakness 23188110 IBIS 4 / 7739
18
 (HPO:0007340) Lower limb muscle weakness 23188110 IBIS 61 / 7739
19
 (HPO:0003431) Decreased motor nerve conduction velocity 23188110 IBIS 51 / 7739
20
 (HPO:0003383) Onion bulb formation 23188110 IBIS 30 / 7739
21
 (HPO:0003448) Decreased sensory nerve conduction velocity 23188110 IBIS 9 / 7739
22
 (HPO:0003477) Peripheral axonal neuropathy 23188110 IBIS 62 / 7739
23
 (HPO:0002936) Distal sensory impairment 23188110 IBIS 96 / 7739
24
 (HPO:0009830) Peripheral neuropathy Very frequent [IBIS] 23188110 IBIS 206 / 7739
25
 (HPO:0002071) Abnormality of extrapyramidal motor function 23188110 IBIS 76 / 7739
26
 (HPO:0001347) Hyperreflexia 23188110 IBIS 363 / 7739
27
 (HPO:0001257) Spasticity 23188110 IBIS 251 / 7739
28
 (HPO:0001258) Spastic paraplegia Very frequent [IBIS] 23188110 IBIS 97 / 7739
29
 (HPO:0100543) Cognitive impairment 23188110 IBIS 230 / 7739
30
 (HPO:0003376) Steppage gait 23188110 IBIS 41 / 7739
31
 (HPO:0001250) Seizures 23188110 IBIS 1245 / 7739
32
 (HPO:0001762) Talipes equinovarus 23188110 IBIS 309 / 7739
33
 (HPO:0006135) Decreased finger mobility 23188110 IBIS 2 / 7739
34
 (HPO:0002079) Hypoplasia of the corpus callosum rare [HPO:skoehler] 23188110 IBIS 161 / 7739
35
 (HPO:0001272) Cerebellar atrophy 23188110 IBIS 197 / 7739
36
 (HPO:0030532) Visual acuity test abnormality 23188110 IBIS 4 / 7739

Associated genes:

C12orf65;

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information:

Clinical Description OMIM Shimazaki et al. (2012) reported 2 Japanese brothers, born of consanguineous parents, with early-onset spastic paraplegia. The brothers had previously been reported by Joshita et al. (1982). The proband developed reduced visual acuity at age 7 years and ...
Molecular genetics OMIM In 2 Japanese brothers, born of consanguineous parents, with autosomal recessive spastic paraplegia-55, Shimazaki et al. (2012) identified a homozygous truncating mutation in the C12ORF65 gene (R132X; 613541.0003). The mutation was found by exome sequencing and confirmed by ...