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Leukoencephalopathy-thalamus and brainstem anomalies-high lactate syndrome(LTBL; COXPD12)

MedGen UID:
1645614
Concept ID:
C4706421
Disease or Syndrome
Synonyms: Combined oxidative phosphorylation deficiency 12; LEUKOENCEPHALOPATHY WITH THALAMUS AND BRAINSTEM INVOLVEMENT AND HIGH LACTATE
SNOMED CT: COXPD12 - combined oxidative phosphorylation defect type 12 (763366000); Combined oxidative phosphorylation defect type 12 (763366000); Leukoencephalopathy, thalamus and brainstem anomalies, high lactate syndrome (763366000)
Modes of inheritance:
No inheritance data available
MedGen UID:
989178
Concept ID:
CN307043
Finding
Source: Orphanet
No information is available in the scientific literature on heredity of the clinical entity.
 
Gene (location): EARS2 (16p12.2)
 
Monarch Initiative: MONDO:0013971
OMIM®: 614924
Orphanet: ORPHA314051

Definition

Combined oxidative phosphorylation deficiency-12 (COXPD12) is an autosomal recessive mitochondrial neurologic disorder characterized by onset in infancy of hypotonia and delayed psychomotor development, or early developmental regression, associated with T2-weighted hyperintensities in the deep cerebral white matter, brainstem, and cerebellar white matter. Serum lactate is increased due to a defect in mitochondrial respiration. There are 2 main phenotypic groups: those with a milder disease course and some recovery of skills after age 2 years, and those with a severe disease course resulting in marked disability (summary by Steenweg et al., 2012). For a discussion of genetic heterogeneity of combined oxidative phosphorylation deficiency, see COXPD1 (609060). [from OMIM]

Additional description

From MedlinePlus Genetics
Leukoencephalopathy with thalamus and brainstem involvement and high lactate (LTBL) is a disorder that affects the brain. LTBL is one of a group of genetic disorders called leukodystrophies, which feature abnormalities of the nervous system's white matter. White matter consists of nerve fibers covered by a fatty substance, called myelin, that insulates nerve fibers and promotes the rapid transmission of nerve impulses.

LTBL is characterized by distinct changes in the brain, which can be seen using magnetic resonance imaging (MRI). These abnormalities typically involve white matter in regions of the brain known as the cerebrum and cerebellum. Abnormalities can also be seen in other regions of the brain, including the brainstem, which is the part that connects to the spinal cord. Affected brain regions include the thalamus, midbrain, pons, and medulla oblongata. Thinning of the tissue that connects the left and right halves of the brain (the corpus callosum) also occurs in people with LTBL. In addition, most affected individuals have a high level of a substance called lactate in the brain and elsewhere in the body.

The severity of the condition varies. Mildly affected individuals usually develop signs and symptoms after the age of 6 months. Loss of mental and movement abilities (psychomotor regression), muscle stiffness (spasticity), and extreme irritability are common, and some people with mild LTBL develop seizures. However, after age 2, the signs and symptoms of the condition improve: affected children regain some psychomotor abilities, seizures are reduced or disappear, MRI results become more normal, and lactate levels drop.

Severely affected individuals have features that begin soon after birth. These infants typically have delayed development of mental and movement abilities (psychomotor delay), weak muscle tone (hypotonia), involuntary muscle tensing (dystonia), muscle spasticity, and seizures. Some have extremely high levels of lactate (lactic acidosis), which can cause serious breathing problems and an abnormal heartbeat. Liver failure occurs in some severely affected infants. In severe cases, the signs and symptoms do not improve and can be life-threatening. In some people with LTBL, the features fall between mild and severe.  https://medlineplus.gov/genetics/condition/leukoencephalopathy-with-thalamus-and-brainstem-involvement-and-high-lactate

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.
Cholestasis
MedGen UID:
925
Concept ID:
C0008370
Disease or Syndrome
Impairment of bile flow due to obstruction in bile ducts.
Hepatomegaly
MedGen UID:
42428
Concept ID:
C0019209
Finding
Abnormally increased size of the liver.
Feeding difficulties
MedGen UID:
65429
Concept ID:
C0232466
Finding
Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it.
Macrovesicular hepatic steatosis
MedGen UID:
373290
Concept ID:
C1837256
Finding
A form of hepatic steatosis characterized by the presence of large, lipid-laden vesicles in the affected hepatocytes.
Dystonic disorder
MedGen UID:
3940
Concept ID:
C0013421
Sign or Symptom
An abnormally increased muscular tone that causes fixed abnormal postures. There is a slow, intermittent twisting motion that leads to exaggerated turning and posture of the extremities and trunk.
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.
Seizure
MedGen UID:
20693
Concept ID:
C0036572
Sign or Symptom
A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.
Corpus callosum, agenesis of
MedGen UID:
104498
Concept ID:
C0175754
Congenital Abnormality
The corpus callosum is the largest fiber tract in the central nervous system and the major interhemispheric fiber bundle in the brain. Formation of the corpus callosum begins as early as 6 weeks' gestation, with the first fibers crossing the midline at 11 to 12 weeks' gestation, and completion of the basic shape by age 18 to 20 weeks (Schell-Apacik et al., 2008). Agenesis of the corpus callosum (ACC) is one of the most frequent malformations in brain with a reported incidence ranging between 0.5 and 70 in 10,000 births. ACC is a clinically and genetically heterogeneous condition, which can be observed either as an isolated condition or as a manifestation in the context of a congenital syndrome (see MOLECULAR GENETICS and Dobyns, 1996). Also see mirror movements-1 and/or agenesis of the corpus callosum (MRMV1; 157600). Schell-Apacik et al. (2008) noted that there is confusion in the literature regarding radiologic terminology concerning partial absence of the corpus callosum, where various designations have been used, including hypogenesis, hypoplasia, partial agenesis, or dysgenesis.
Bradykinesia
MedGen UID:
115925
Concept ID:
C0233565
Sign or Symptom
Bradykinesia literally means slow movement, and is used clinically to denote a slowness in the execution of movement (in contrast to hypokinesia, which is used to refer to slowness in the initiation of movement).
Leukoencephalopathy
MedGen UID:
78722
Concept ID:
C0270612
Disease or Syndrome
This term describes abnormality of the white matter of the cerebrum resulting from damage to the myelin sheaths of nerve cells.
Hypoplasia of the corpus callosum
MedGen UID:
138005
Concept ID:
C0344482
Congenital Abnormality
Underdevelopment of the corpus callosum.
Dysplastic corpus callosum
MedGen UID:
98128
Concept ID:
C0431369
Congenital Abnormality
Dysplasia and dysgenesis of the corpus callosum are nonspecific descriptions that imply defective development of the corpus callosum. The term dysplasia is applied when the morphology of the corpus callosum is altered as a congenital trait. For instance, the corpus callosum may be hump-shaped, kinked, or a striped corpus callosum that lacks an anatomically distinct genu and splenium.
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.
Spastic tetraparesis
MedGen UID:
658719
Concept ID:
C0575059
Disease or Syndrome
Spastic weakness affecting all four limbs.
Developmental regression
MedGen UID:
324613
Concept ID:
C1836830
Disease or Syndrome
Loss of developmental skills, as manifested by loss of developmental milestones.
Absent speech
MedGen UID:
340737
Concept ID:
C1854882
Finding
Complete lack of development of speech and language abilities.
Delayed CNS myelination
MedGen UID:
867393
Concept ID:
C4021758
Anatomical Abnormality
Delayed myelination in the central nervous system.
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.
Poor head control
MedGen UID:
322809
Concept ID:
C1836038
Finding
Difficulty to maintain correct position of the head while standing or sitting. Infant head lag is observed when the head seems to flop around or lags posteriorly behind the trunk. Several articles have maintained that head lag should be absent by age 3 to 4 months.
Axial hypotonia
MedGen UID:
342959
Concept ID:
C1853743
Finding
Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk.
Neonatal hypotonia
MedGen UID:
412209
Concept ID:
C2267233
Disease or Syndrome
Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period.
Ragged-red muscle fibers
MedGen UID:
477048
Concept ID:
C3275417
Finding
An abnormal appearance of muscle fibers observed on muscle biopsy. Ragged red fibers can be visualized with Gomori trichrome staining as irregular and intensely red subsarcolemmal zones, whereas the normal myofibrils are green. The margins of affect fibers appear red and ragged. The ragged-red is due to the accumulation of abnormal mitochondria below the plasma membrane of the muscle fiber, leading to the appearance of a red rim and speckled sarcoplasm.
Lactic acidosis
MedGen UID:
1717
Concept ID:
C0001125
Disease or Syndrome
An abnormal buildup of lactic acid in the body, leading to acidification of the blood and other bodily fluids.
Elevated circulating aspartate aminotransferase concentration
MedGen UID:
57497
Concept ID:
C0151904
Finding
The concentration of aspartate aminotransferase (AST) in the blood circulation is above the upper limit of normal.
Elevated circulating alanine aminotransferase concentration
MedGen UID:
57740
Concept ID:
C0151905
Finding
An abnormally high concentration in the circulation of alanine aminotransferase (ALT).
Elevated circulating alpha-fetoprotein concentration
MedGen UID:
65916
Concept ID:
C0235971
Finding
Concentration of alpha-fetoprotein in the blood circulation above the upper limit of normal.
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).
Cleft palate
MedGen UID:
756015
Concept ID:
C2981150
Congenital Abnormality
Cleft palate is a developmental defect of the palate resulting from a failure of fusion of the palatine processes and manifesting as a separation of the roof of the mouth (soft and hard palate).
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).
Ophthalmoplegia
MedGen UID:
45205
Concept ID:
C0029089
Sign or Symptom
Paralysis of one or more extraocular muscles that are responsible for eye movements.
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 III
MedGen UID:
460434
Concept ID:
C3149083
Finding
A reduction in the activity of the mitochondrial respiratory chain complex III, 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.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  

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