U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

Mitochondrial complex 4 deficiency, nuclear type 17(MC4DN17)

MedGen UID:
1730423
Concept ID:
C5436718
Disease or Syndrome
Synonym: MITOCHONDRIAL COMPLEX IV DEFICIENCY, NUCLEAR TYPE 17
 
Gene (location): COA8 (14q32.33)
 
Monarch Initiative: MONDO:0033652
OMIM®: 619061

Definition

Mitochondrial complex IV deficiency nuclear type 17 (MC4DN17) is an autosomal recessive neurometabolic disorder with somewhat variable clinical manifestations and severity. Most affected individuals present in early childhood with motor and gait difficulties after normal early development. These motor abnormalities progress to spastic tetraparesis, sometimes resulting in loss of ambulation. Many patients also show episodic developmental regression: some have impaired cognition and dysarthria, although others have normal speech and cognition. More variable features include seizures and sensorimotor polyneuropathy. The clinical features tend to stabilize over time. Brain imaging shows a cavitating leukodystrophy, and laboratory studies show variably decreased levels and activity of mitochondrial respiratory complex IV in patient tissues (Melchionda et al., 2014). For a discussion of genetic heterogeneity of mitochondrial complex IV (cytochrome c oxidase) deficiency, see 220110. [from OMIM]

Clinical features

From HPO
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.
Seizure
MedGen UID:
20693
Concept ID:
C0036572
Sign or Symptom
A seizure is an intermittent abnormality of nervous system physiology characterised by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.
Cavitating leukodystrophy
MedGen UID:
542952
Concept ID:
C0270725
Disease or Syndrome
A type of leukodystrophy characterized by multiple small cavitations typically in the periventricular and deep cerebral white matter. The cavitations are visible as a central cavity with cerebrospinal fluid-like signal intensity.
Delayed speech and language development
MedGen UID:
105318
Concept ID:
C0454644
Finding
A degree of language development that is significantly below the norm for a child of a specified age.
Spastic tetraparesis
MedGen UID:
658719
Concept ID:
C0575059
Disease or Syndrome
Spastic weakness affecting all four limbs.
Sensorimotor neuropathy
MedGen UID:
207266
Concept ID:
C1112256
Disease or Syndrome
Developmental regression
MedGen UID:
324613
Concept ID:
C1836830
Disease or Syndrome
Loss of developmental skills, as manifested by loss of developmental milestones.
Intellectual disability
MedGen UID:
811461
Concept ID:
C3714756
Mental or Behavioral Dysfunction
Intellectual disability, previously referred to as mental retardation, is characterized by subnormal intellectual functioning that occurs during the developmental period. It is defined by an IQ score below 70.
Cytochrome C oxidase-negative muscle fibers
MedGen UID:
867360
Concept ID:
C4021724
Finding
An abnormally reduced activity of the enzyme cytochrome C oxidase in muscle tissue.
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.

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...