Related Experiment Video
Updated: Jul 11, 2026
06:40
Visualization of Chondrocyte Intercalation and Directional Proliferation via Zebrabow Clonal Cell Analysis in the Embryonic Meckel’s Cartilage
Published on: October 21, 2015
A disorder resembling pseudoachondroplasia but without COMP mutation
J W Spranger1, B Zabel, J Kennedy
1Children's Hospital, University of Mainz, Germany. spranger@ggc.org
American Journal of Medical Genetics. Part A
|November 20, 2004
Summary
This study describes siblings with severe skeletal dysplasia resembling pseudoachondroplasia (PA), but without COMP gene mutations. This suggests a potential new genetic cause for this rare dwarfism disorder.
Area of Science:
- Genetics
- Skeletal Dysplasias
- Molecular Biology
Background:
- Pseudoachondroplasia (PA) is an autosomal dominant skeletal dysplasia.
- It is characterized by disproportionate short stature, ligamentous laxity, and irregular ossification.
- Mutations in the COMP gene are the known cause of PA.
Observation:
- This study identified siblings with severe bone changes similar to very severe PA.
- These siblings were born to unaffected parents, ruling out typical inheritance.
- Genetic sequencing of the COMP gene in these siblings revealed no mutations.
Findings:
- The affected siblings present with a disorder resembling PA.
- The condition appears to stem from a defect in an extracellular matrix protein other than COMP.
- This suggests a novel genetic etiology for severe dwarfism.
Implications:
- This finding expands the genetic understanding of skeletal dysplasias.
- It highlights the possibility of other extracellular matrix protein defects causing PA-like conditions.
- Early suspicion in severe dwarfism cases with specific bone abnormalities is warranted.
Related Concept Videos
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,...
01:43Sex-linked Disorders
Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked.
01:29Nondisjunction
During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.
01:27Adrenal Gland Disorders
Adrenal gland disorders manifest when the production of adrenal hormones deviates from the norm, resulting in either excessive or insufficient concentrations.
Adrenal insufficiency, characterized by insufficient cortisol and aldosterone production, leads to conditions like Addison's disease. This disorder, affecting the adrenal cortex, exhibits symptoms such as skin bronzing, dehydration, low blood pressure, fatigue, and weight loss. Congenital adrenal hyperplasia, a genetic ailment causing...
Adrenal insufficiency, characterized by insufficient cortisol and aldosterone production, leads to conditions like Addison's disease. This disorder, affecting the adrenal cortex, exhibits symptoms such as skin bronzing, dehydration, low blood pressure, fatigue, and weight loss. Congenital adrenal hyperplasia, a genetic ailment causing...
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...
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...