Related Experiment Video
Updated: Aug 3, 2026
06:41
In Vivo Functional Study of Disease-associated Rare Human Variants Using Drosophila
Published on: August 20, 2019
COL9A3: A third locus for multiple epiphyseal dysplasia
P Paassilta1, J Lohiniva, S Annunen
1Collagen Research Unit, Biocenter and Department of Medical Biochemistry, University of Oulu, Oulu, Finland.
American Journal of Human Genetics
|March 26, 1999
Summary
Multiple epiphyseal dysplasia (MED) is a genetic disorder causing short stature and early arthritis. Researchers identified a new gene, COL9A3, as a third cause of MED, uncovering a novel mutation responsible for the condition.
Area of Science:
- Genetics
- Molecular Biology
- Orthopedics
Background:
- Multiple epiphyseal dysplasia (MED) is a heterogeneous skeletal disorder.
- It is characterized by short stature and early-onset osteoarthritis.
- Existing genetic loci (EDM1, EDM2) do not explain all MED cases.
Purpose of the Study:
- To identify the genetic cause of MED in a family not linked to known loci.
- To investigate the role of COL9A3 as a potential MED gene.
- To characterize the identified mutation and its effect on the protein.
Main Methods:
- Clinical and radiological evaluation of the affected family.
- Linkage analysis with candidate genes (COMP, COL9A1, COL9A2, COL9A3).
- Mutation analysis of COL9A3 in affected individuals.
Main Results:
- Linkage analysis excluded COMP, COL9A1, and COL9A2.
- A significant linkage was observed with the COL9A3 locus.
- A splice-site mutation (A-->T transversion) in COL9A3 was identified, causing exon skipping and protein alteration.
- This is the first identified disease-causing mutation in COL9A3.
Conclusions:
- COL9A3 is a third causative gene for Multiple Epiphyseal Dysplasia.
- Mutations in COL9A3 represent a novel genetic cause of MED.
- This finding expands the genetic understanding of skeletal dysplasias.
Related Concept Videos
01:39Epistasis
In addition to multiple alleles at the same locus influencing traits, numerous genes or alleles at different locations may interact and influence phenotypes in a phenomenon called epistasis. For example, rabbit fur can be black or brown depending on whether the animal is homozygous dominant or heterozygous at a TYRP1 locus. However, if the rabbit is also homozygous recessive at a locus on the tyrosinase gene (TYR), it will have an unshaded coat that appears white, regardless of its TYRP1...
01:33Pleiotropy
Pleiotropy is the phenomenon in which a single gene impacts multiple, seemingly unrelated phenotypic traits. For example, defects in the SOX10 gene cause Waardenburg Syndrome Type 4, or WS4, which can cause defects in pigmentation, hearing impairments, and an absence of intestinal contractions necessary for elimination. This diversity of phenotypes results from the expression pattern of SOX10 in early embryonic and fetal development. SOX10 is found in neural crest cells that form melanocytes,...
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
01:09Epistasis Analysis
Although Mendel chose seven unrelated traits in peas to study gene segregation, most traits involve multiple gene interactions that create a spectrum of phenotypes. When the interaction of various genes or alleles at different locations influences a phenotype, this is called epistasis. Epistasis often involves one gene masking or interfering with the expression of another (antagonistic epistasis). Epistasis often occurs when different genes are part of the same biochemical pathway. The...
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
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy, or HCM, is an autosomal dominant genetic disorder characterized by asymmetric left ventricular hypertrophy without ventricular dilation. It is more common in men and is typically diagnosed in young, athletic adults.EtiologyHCM is primarily genetic and is caused by mutations in genes encoding sarcomeric proteins. Researchers have identified over 1400 mutations across at least 11 different genes. Among these, the most frequently occurring mutations are found in the...