Hereditary glomerulopathy associated with a mitochondrial tRNA(Leu) gene mutation
H I Cheong1, J H Chae, J S Kim
1Department of Pediatrics, Seoul National University Children's Hospital, Korea. cheonghi@plaza.snu.ac.kr
Pediatric Nephrology (Berlin, Germany)
|August 19, 1999
Summary
The mitochondrial DNA 3243 mutation causes progressive glomerulopathy, mimicking Alport syndrome. This finding expands the spectrum of mitochondrial cytopathies and aids in diagnosing kidney disease.
Area of Science:
- Nephrology
- Genetics
- Mitochondrial Biology
Background:
- Hereditary glomerulopathy and hearing loss can resemble Alport syndrome.
- The mitochondrial DNA 3243 A-to-G transition is linked to MELAS syndrome (myopathy, encephalopathy, lactic acidosis, and stroke-like episodes).
Observation:
- A study screened 27 patients with Alport syndrome-like kidney disease for the 3243 mitochondrial mutation.
- One patient, a girl with a positive family history, tested positive for the mutation.
Findings:
- The patient exhibited progressive glomerulopathy, hearing loss, and neurological symptoms, consistent with mitochondrial cytopathies.
- Key distinguishing features from Alport syndrome included absence of hematuria, severe kidney disease in a female, focal segmental glomerulosclerosis without glomerular capillary wall changes, and steroid-induced diabetes.
Implications:
- Progressive glomerulopathy should be considered within the spectrum of mitochondrial cytopathies, particularly in MELAS syndrome cases.
- The 3243 mitochondrial mutation is a crucial consideration in secondary focal segmental glomerulosclerosis and the differential diagnosis of Alport syndrome.
Related Concept Videos
01:39Mutations
Overview
01:31Translation
Lesson: Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
02:59Animal Mitochondrial Genetics
Among all the organelles in an animal cell, only mitochondria have their own independent genomes. Animal mitochondrial DNA is a double-stranded, closed-circular molecule with around 20,000 base pairs. Mitochondrial DNA is unique in that one of its two strands, the heavy, or H, -strand is guanine rich, whereas the complementary strand is cytosine rich and called the light, or L, -strand. Compared to nuclear DNA, mitochondrial DNA has a very low percentage of non-coding regions and is marked by...
01:48ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
01:31Translation
Lesson: Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
01:20Inborn Errors of Metabolism
Phenylketonuria (PKU) is a protein metabolism disorder characterized by high blood levels of the amino acid phenylalanine. This results from a mutation in the gene responsible for phenylalanine hydroxylase, an enzyme that converts phenylalanine into tyrosine. When this enzyme is deficient, phenylalanine builds up in the blood, leading to symptoms such as vomiting, rashes, seizures, growth deficiency, and severe mental retardation. An early diagnosis and a diet restricting phenylalanine intake...