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Combined oxidative phosphorylation defect type 7(COXPD7)

MedGen UID:
462151
Concept ID:
C3150801
Disease or Syndrome
Synonym: Combined oxidative phosphorylation deficiency 7
SNOMED CT: Combined oxidative phosphorylation defect type 7 (763204003); COXPD7 - combined oxidative phosphorylation defect type 7 (763204003)
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): MTRFR (12q24.31)
 
Monarch Initiative: MONDO:0013306
OMIM®: 613559
Orphanet: ORPHA254930

Definition

A rare mitochondrial disease due to a defect in mitochondrial protein synthesis with a variable phenotype that includes onset in infancy or early childhood of failure to thrive and psychomotor regression (after initial normal development), as well as ocular manifestations (such as ptosis, nystagmus, optic atrophy, ophthalmoplegia and reduced vision). Additional manifestations include bulbar paresis with facial weakness, hypotonia, difficulty chewing, dysphagia, mild dysarthria, ataxia, global muscle atrophy, and areflexia. It has a relatively slow disease progression with patients often living into the third decade of life. [from SNOMEDCT_US]

Clinical features

From HPO
Failure to thrive
MedGen UID:
746019
Concept ID:
C2315100
Disease or Syndrome
Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm.
Dysphagia
MedGen UID:
41440
Concept ID:
C0011168
Disease or Syndrome
Difficulty in swallowing.
Paralytic ileus
MedGen UID:
18293
Concept ID:
C0030446
Disease or Syndrome
An ileus caused by abdominal or pelvic surgery, infections, disorders that affect the muscles and nerves, and medications. Signs and symptoms include those of intestinal obstruction.
Cerebellar ataxia
MedGen UID:
849
Concept ID:
C0007758
Disease or Syndrome
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).
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.
Polyneuropathy
MedGen UID:
57502
Concept ID:
C0152025
Disease or Syndrome
A generalized disorder of peripheral nerves.
Areflexia
MedGen UID:
115943
Concept ID:
C0234146
Finding
Absence of neurologic reflexes such as the knee-jerk reaction.
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.
Developmental regression
MedGen UID:
324613
Concept ID:
C1836830
Disease or Syndrome
Loss of developmental skills, as manifested by loss of developmental milestones.
Distal sensory impairment
MedGen UID:
335722
Concept ID:
C1847584
Finding
An abnormal reduction in sensation in the distal portions of the extremities.
Elevated brain lactate level by MRS
MedGen UID:
868368
Concept ID:
C4022762
Finding
An increase in the level of lactate in the brain identified by magnetic resonance spectroscopy (MRS).
Facial paralysis
MedGen UID:
5101
Concept ID:
C0015469
Disease or Syndrome
Complete loss of ability to move facial muscles innervated by the facial nerve (i.e., the seventh cranial nerve).
Hypotonia
MedGen UID:
10133
Concept ID:
C0026827
Finding
Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.
Muscle weakness
MedGen UID:
57735
Concept ID:
C0151786
Finding
Reduced strength of muscles.
Muscular atrophy
MedGen UID:
892680
Concept ID:
C0541794
Pathologic Function
The presence of skeletal muscular atrophy (which is also known as amyotrophy).
Facial diplegia
MedGen UID:
322796
Concept ID:
C1836003
Finding
Facial diplegia refers to bilateral facial palsy (bilateral facial palsy is much rarer than unilateral facial palsy).
Increased circulating lactate concentration
MedGen UID:
332209
Concept ID:
C1836440
Finding
Abnormally increased level of blood lactate (2-hydroxypropanoic acid). Lactate is produced from pyruvate by lactate dehydrogenase during normal metabolism. The terms lactate and lactic acid are often used interchangeably but lactate (the component measured in blood) is strictly a weak base whereas lactic acid is the corresponding acid. Lactic acidosis is often used clinically to describe elevated lactate but should be reserved for cases where there is a corresponding acidosis (pH below 7.35).
Impaired mastication
MedGen UID:
66779
Concept ID:
C0239043
Finding
An abnormal reduction in the ability to masticate (chew), i.e., in the ability to crush and ground food in preparation for swallowing.
Ptosis
MedGen UID:
2287
Concept ID:
C0005745
Disease or Syndrome
The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective).
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.
Ophthalmoplegia
MedGen UID:
45205
Concept ID:
C0029089
Sign or Symptom
Paralysis of one or more extraocular muscles that are responsible for eye movements.
Optic atrophy
MedGen UID:
18180
Concept ID:
C0029124
Disease or Syndrome
Atrophy of the optic nerve. Optic atrophy results from the death of the retinal ganglion cell axons that comprise the optic nerve and manifesting as a pale optic nerve on fundoscopy.
Strabismus
MedGen UID:
21337
Concept ID:
C0038379
Disease or Syndrome
A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error.
External ophthalmoplegia
MedGen UID:
57662
Concept ID:
C0162292
Disease or Syndrome
Paralysis of the external ocular muscles.
Visual impairment
MedGen UID:
777085
Concept ID:
C3665347
Finding
Visual impairment (or vision impairment) is vision loss (of a person) to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive correction, medication, or surgery.
Decreased activity of mitochondrial complex I
MedGen UID:
393796
Concept ID:
C2677650
Finding
A reduction in the activity of the mitochondrial respiratory chain complex I, which is part of the electron transport chain in mitochondria.
Decreased activity of mitochondrial complex IV
MedGen UID:
866520
Concept ID:
C4020800
Finding
A reduction in the activity of the mitochondrial respiratory chain complex IV, which is part of the electron transport chain in mitochondria.
Decreased activity of mitochondrial ATP synthase complex
MedGen UID:
892442
Concept ID:
C4023125
Finding
A reduction in the activity of the mitochondrial proton-transporting ATP synthase complex, which makes ATP via oxidative phosphorylation, and is sometimes described as Complex V of the electron transport chain.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
Follow this link to review classifications for Combined oxidative phosphorylation defect type 7 in Orphanet.

Recent clinical studies

Etiology

Yaplito-Lee J, Weintraub R, Jamsen K, Chow CW, Thorburn DR, Boneh A
J Pediatr 2007 Apr;150(4):407-11. doi: 10.1016/j.jpeds.2006.12.047. PMID: 17382120

Diagnosis

Zhang Q, Ouyang Q, Xiang J, Li H, Lv H, An Y
Genes (Basel) 2023 Feb 22;14(3) doi: 10.3390/genes14030552. PMID: 36980825Free PMC Article
Yaplito-Lee J, Weintraub R, Jamsen K, Chow CW, Thorburn DR, Boneh A
J Pediatr 2007 Apr;150(4):407-11. doi: 10.1016/j.jpeds.2006.12.047. PMID: 17382120
Petersen KF, Dufour S, Befroy D, Garcia R, Shulman GI
N Engl J Med 2004 Feb 12;350(7):664-71. doi: 10.1056/NEJMoa031314. PMID: 14960743Free PMC Article

Prognosis

Yaplito-Lee J, Weintraub R, Jamsen K, Chow CW, Thorburn DR, Boneh A
J Pediatr 2007 Apr;150(4):407-11. doi: 10.1016/j.jpeds.2006.12.047. PMID: 17382120
Petersen KF, Dufour S, Befroy D, Garcia R, Shulman GI
N Engl J Med 2004 Feb 12;350(7):664-71. doi: 10.1056/NEJMoa031314. PMID: 14960743Free PMC Article

Clinical prediction guides

Zhang Q, Ouyang Q, Xiang J, Li H, Lv H, An Y
Genes (Basel) 2023 Feb 22;14(3) doi: 10.3390/genes14030552. PMID: 36980825Free PMC Article
Petersen KF, Dufour S, Befroy D, Garcia R, Shulman GI
N Engl J Med 2004 Feb 12;350(7):664-71. doi: 10.1056/NEJMoa031314. PMID: 14960743Free PMC Article

Recent systematic reviews

Zhang Q, Ouyang Q, Xiang J, Li H, Lv H, An Y
Genes (Basel) 2023 Feb 22;14(3) doi: 10.3390/genes14030552. PMID: 36980825Free PMC Article
Dogan AE, Yuksel C, Du F, Chouinard VA, Öngür D
Neuropsychopharmacology 2018 Jul;43(8):1681-1690. Epub 2018 Mar 14 doi: 10.1038/s41386-018-0041-9. PMID: 29581538Free PMC Article