Related Experiment Video
Updated: Jul 14, 2026
07:43
Modeling Charcot-Marie-Tooth Disease In Vitro by Transfecting Mouse Primary Motoneurons
Published on: January 7, 2019
Phenotype of Charcot-Marie-Tooth disease Type 2.
H M E Bienfait1, F Baas, J H T M Koelman
1Department of Neurology, Academic Medical Centre, University of Amsterdam, The Netherlands.
Neurology
|May 16, 2007
Summary
Charcot-Marie-Tooth disease (CMT) Type 2 presents a uniform clinical picture of distal weakness, though genetic causes remain elusive in many families. This study characterized the phenotype and identified mutations in MFN2, BSCL2, and RAB7 genes.
Area of Science:
- Neurology
- Genetics
- Clinical Electrophysiology
Background:
- Charcot-Marie-Tooth disease (CMT) is a group of inherited disorders affecting peripheral nerves.
- CMT Type 2 is characterized by axonal neuropathy, distinguishing it from the demyelinating forms like CMT Type 1.
- Understanding the clinical and genetic spectrum of CMT Type 2 is crucial for diagnosis and management.
Purpose of the Study:
- To delineate the clinical and electrophysiologic characteristics of Charcot-Marie-Tooth disease (CMT) Type 2.
- To identify genetic mutations associated with CMT Type 2 in affected families.
- To assess the genetic heterogeneity of CMT Type 2.
Main Methods:
- DNA analysis was used to exclude other forms of CMT and specific gene mutations.
- Genetic analysis focused on known CMT Type 2 genes.
- Clinical and electrophysiologic data were collected from 18 families comprising 61 affected individuals.
Main Results:
- The majority of patients (90%) retained ambulation.
- Proximal leg weakness (13%) and asymmetrical features (15%) were observed.
- Normal or brisk reflexes (36%) and extensor plantar responses (10 patients) were noted.
- Causative mutations were identified in only 17% of families, specifically in MFN2, BSCL2, and RAB7 genes.
Conclusions:
- Charcot-Marie-Tooth disease (CMT) Type 2 exhibits a consistent clinical phenotype of symmetric distal weakness, atrophy, and sensory loss.
- Variations such as brisk reflexes and extensor plantar responses are part of the CMT Type 2 spectrum.
- Genetic underpinnings of CMT Type 2 remain largely unidentified, highlighting the need for further research.
Related Concept Videos
01:15Teeth
The formation of teeth, also known as odontogenesis, is a complex process that begins in utero, around the sixth week of embryonic development. There are three stages to this process: the bud stage, the cap stage, and the bell stage.
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
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,...
01:24Type II Diabetes II: Pathophysiology
PathophysiologyType 2 diabetes mellitus (T2DM ) is a chronic metabolic disorder characterized by insulin resistance and progressive pancreatic β-cell dysfunction, leading to impaired glucose homeostasis. It results from interactions among genetic predisposition, environmental factors, and metabolic stressors, such as overnutrition and a sedentary lifestyle.Insulin Resistance and Glucose DysregulationEarly T2DM involves insulin resistance in skeletal muscle, adipose tissue, and the liver.
01:26Type I Diabetes II: Pathophysiology
Type 1 diabetes mellitus arises from an immune-mediated destruction of pancreatic β-cells, resulting in an absolute deficiency of insulin. This process develops in genetically susceptible individuals when autoimmunity, environmental exposures, and immunologic dysregulation converge to trigger a targeted attack on the insulin-producing cells of the pancreas. The β-cells are located within the islets of Langerhans and are essential for regulating blood glucose by facilitating cellular uptake of...
01:21Tooth Anatomy
The human tooth enables us to eat a variety of foods, speak clearly, and even aid in shaping our faces. Teeth are composed of various elements that work together. Here's a detailed look at the anatomy of a human tooth.
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or grinding food.
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or grinding food.
01:21Chronic Pancreatitis II: Pathophysiology
Chronic pancreatitis is a progressive and irreversible inflammation of the pancreas, most often caused by long-term alcohol abuse, but it can also be related to ductal obstruction, smoking, or genetic factors.Chronic pancreatitis occurs when the pancreas is repeatedly exposed to harmful agents like alcohol, smoking, ductal obstruction, or genetic predisposition. These factors lead to the release of toxic metabolites and inflammatory cytokines, sustaining chronic inflammation in the pancreatic...