U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

Mitochondrial complex 4 deficiency, nuclear type 18(MC4DN18)

MedGen UID:
1752734
Concept ID:
C5436720
Disease or Syndrome
Synonym: MITOCHONDRIAL COMPLEX IV DEFICIENCY, NUCLEAR TYPE 18
 
Gene (location): COX6A2 (16p11.2)
 
Monarch Initiative: MONDO:0033653
OMIM®: 619062

Definition

Mitochondrial complex IV deficiency nuclear type 18 (MC4DN18) is an autosomal recessive metabolic disorder that primarily affects skeletal muscle tissue. Affected individuals present in infancy with hypotonia, limb muscle weakness, and high-arched palate. The severity of the disorder is variable: some patients may only have gait difficulties, whereas others may also have significant respiratory insufficiency and cardiomyopathy. Death in infancy has been reported. Patient skeletal muscle shows decreased levels and activity of mitochondrial respiratory complex IV (Inoue et al., 2019). For a discussion of genetic heterogeneity of mitochondrial complex IV (cytochrome c oxidase) deficiency, see 220110. [from OMIM]

Clinical features

From HPO
Muscle weakness
MedGen UID:
57735
Concept ID:
C0151786
Finding
Reduced strength of muscles.
Weakness of facial musculature
MedGen UID:
98103
Concept ID:
C0427055
Disease or Syndrome
Reduced strength of one or more muscles innervated by the facial nerve (the seventh cranial nerve).
Generalized hypotonia
MedGen UID:
346841
Concept ID:
C1858120
Finding
Generalized muscular hypotonia (abnormally low muscle tone).
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.
Neonatal respiratory distress
MedGen UID:
924182
Concept ID:
C4281993
Finding
Respiratory difficulty as newborn.
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).
Increased serum pyruvate
MedGen UID:
376596
Concept ID:
C1849488
Finding
An increased concentration of pyruvate in the blood.
Increased intramyocellular lipid droplets
MedGen UID:
866481
Concept ID:
C4020730
Finding
An abnormal increase in intracellular lipid droplets In a muscle. The number and size of these drops can increase with somd disorders of lipid metabolism affecting muscle. See PMID 20691590 for histological images.
High palate
MedGen UID:
66814
Concept ID:
C0240635
Congenital Abnormality
Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective).
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.

Recent clinical studies

Etiology

Wortmann SB, Rodenburg RJ, Jonckheere A, de Vries MC, Huizing M, Heldt K, van den Heuvel LP, Wendel U, Kluijtmans LA, Engelke UF, Wevers RA, Smeitink JA, Morava E
Brain 2009 Jan;132(Pt 1):136-46. Epub 2008 Nov 16 doi: 10.1093/brain/awn296. PMID: 19015156

Diagnosis

Wortmann SB, Rodenburg RJ, Jonckheere A, de Vries MC, Huizing M, Heldt K, van den Heuvel LP, Wendel U, Kluijtmans LA, Engelke UF, Wevers RA, Smeitink JA, Morava E
Brain 2009 Jan;132(Pt 1):136-46. Epub 2008 Nov 16 doi: 10.1093/brain/awn296. PMID: 19015156
Houstek J, Klement P, Floryk D, Antonická H, Hermanská J, Kalous M, Hansíková H, Hout'ková H, Chowdhury SK, Rosipal T, Kmoch S, Stratilová L, Zeman J
Hum Mol Genet 1999 Oct;8(11):1967-74. doi: 10.1093/hmg/8.11.1967. PMID: 10484764

Prognosis

Houstek J, Klement P, Floryk D, Antonická H, Hermanská J, Kalous M, Hansíková H, Hout'ková H, Chowdhury SK, Rosipal T, Kmoch S, Stratilová L, Zeman J
Hum Mol Genet 1999 Oct;8(11):1967-74. doi: 10.1093/hmg/8.11.1967. PMID: 10484764

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...