What is Mitochondrial Complex I Deficiency, Nucelar Type?
Mitochondrial Complex I Deficiency is a syndrome caused by the lack of a protein complex known as complex I. It is a mitochondrial cell structure responsible for a process that enables many of the cells in the body to generate energy. Symptoms of the syndrome affect mainly the nervous system, skeletal muscles, and the heart.
It occurs in around 1 in 8500 people. Mitochondrial complex I deficiency is the most common mitochondrial disease.
This syndrome is also known as:
Mitochondrial NADH Dehydrogenase Component Of Complex I, Deficiency Of; NADH dehydrogenase deficiency (partial); NADH-coenzyme Q Reductase Deficiency; NADH-CoQ reductase deficiency NADH:Q(1) Oxidoreductase Deficiency
What gene changes cause Mitochondrial Complex I Deficiency, Nuclear Type?
Changes in many genes are responsible for causing the syndrome, including both nuclear and mitochondrial genes, upto date, 39 nuclear genes have been described; however, mitochondrial genes have subtly different clinical characteristics. Nuclear syndromes are inherited in an X-linked or autosomal recessive pattern depending on which gene mutation occurs.
Autosomal recessive inheritance means an affected individual receives one copy of a mutated gene from each of their parents, giving them two copies of a mutated gene. Parents, who carry only one copy of the gene mutation will not generally show any symptoms but have a 25% chance of passing the copies of the gene mutations onto each of their children.
What are the main symptoms of Mitochondrial Complex I Deficiency, Nuclear Type?
The syndrome has many symptoms.
The main neurological symptoms include abnormal brain function, epilepsy, intellectual disability, involuntary movements, and problems coordinating movements.
Features affecting physical activity include low muscle tone, muscle pain, and extreme tiredness following physical activity. Higher than normal levels of lactic acid in the blood can also cause nausea, vomiting, and rapid breathing. It also has the potential to be life-threatening if left untreated.
Heart, liver, and kidney issues are potential symptoms. As is vision impairment.
Some affected individuals have symptoms that as a group are caused by a specific syndrome. That is mitochondrial complex I deficiency triggers enough syndrome. Leigh syndrome is one such example of this.
Possible clinical traits/features:
Global developmental delay, Growth delay, Hepatic failure, Hypertrophic cardiomyopathy, Hyperreflexia, Hypoglycemia, Hyporeflexia, Increased CSF lactate, Spasticity, Mitochondrial inheritance, X-linked dominant inheritance, Ptosis, Strabismus, Phenotypic variability, Vomiting, Respiratory failure, Lactic acidosis, Lethargy, Leukodystrophy, Abnormal mitochondria in muscle tissue, Progressive macrocephaly, Muscular hypotonia, Muscle weakness, Exercise intolerance, Feeding difficulties in infancy, Failure to thrive, Coma, Developmental regression, Seizure, Autosomal recessive inheritance, Sensorineural hearing impairment, Nystagmus, Optic disc pallor, Skeletal muscle atrophy, Acute necrotizing encephalopathy, Cerebellar atrophy, Cerebral edema, Ataxia, Babinski sign, Blindness.
How is it diagnosed?
To find out if someone has a diagnosis of Mitochondrial Complex I, Deficiency, Nuclear Type, it is important to have a consultation and evaluation with a clinical genetic specialist. Specialists may also suggest specific genetic testing or other types of tests to help reach a diagnosis. FDNA’s AI technology can help speed up the diagnostic process by analyzing facial features and other health information.
