Related Experiment Video
Updated: May 19, 2026
12:37
Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
[Obesity caused by melanocortin-4 receptor mutations]
Linda van den Berg1, Miriam Glorie-Docter, Erica van den Akker
1Leids Universitair Medisch Centrum, afd. Kindergeneeskunde, Leiden, the Netherlands.
Nederlands Tijdschrift Voor Geneeskunde
|August 9, 2012
Summary
Melanocortin-4 receptor (MC4R) gene mutations cause monogenic obesity in 2% of Dutch children. DNA diagnostics can identify these mutations, which are linked to early-onset extreme overweight and hyperphagia.
Area of Science:
- Genetics
- Endocrinology
- Pediatrics
Context:
- Obesity arises from genetic and lifestyle factors.
- Monogenic obesity results from single gene mutations.
- MC4R gene mutations are the most common cause of monogenic obesity.
Purpose:
- To summarize the role of MC4R gene mutations in monogenic obesity.
- To describe the clinical phenotype associated with MC4R mutations.
- To highlight diagnostic approaches and current treatment limitations.
Summary:
- MC4R gene mutations are found in approximately 2% of Dutch children with obesity.
- Homozygous and compound heterozygous MC4R mutations lead to early-onset extreme obesity and hyperphagia.
- Heterozygous MC4R mutations present a subtler phenotype, challenging clinical distinction.
Impact:
- Identifies a significant genetic cause of childhood obesity.
- Emphasizes the importance of genetic diagnostics for MC4R mutations.
- Underscores the current lack of specific drug treatments for MC4R-related obesity.
Related Concept Videos
01:24Obesity
The Body Mass Index (BMI) is a numerical value derived from a person's weight and height, used to categorize individuals into weight ranges. It is calculated using the formula: weight in kilograms divided by height in meters squared. Obesity is a health condition characterized by excessive accumulation of adipose tissue that poses health risks, often diagnosed with a BMI ≥ 30. This excess fat storage occurs when surplus dietary calories are converted into triglycerides and stored in adipocytes...
01:20Pharmacokinetics in Obese Patients: Drug Metabolism and Excretion
Drug metabolism, a critical process in the liver, involves two primary phases: Phase I reactions and Phase II conjugation. Obesity introduces significant alterations in this metabolic process, primarily due to fatty infiltration of the liver, leading to conditions such as nonalcoholic fatty liver disease (NAFLD). This condition can modify the activities of both Phase I and II enzymes, impacting how drugs are metabolized in obese patients.Phase I metabolism sees variable effects across...
01:25Pharmacokinetics in Obese Patients: Drug Absorption and Distribution
Obesity significantly alters the pharmacokinetic processes of drug absorption and distribution, presenting unique challenges in medical treatment. The increased fat tissue and decreased lean muscle in obese individuals can significantly affect how drugs are absorbed into the body and distributed across different tissues. This alteration can lead to variances in the effectiveness and safety of medications, necessitating adjustments in dosing or drug selection for obese patients.One notable...
01:30Skin Cancer
Skin cancer is a type of cancer that occurs when there is an abnormal growth of skin cells, usually triggered by damage to the DNA within the skin cells. It is primarily caused by exposure to ultraviolet (UV) radiation from the sun or artificial sources like tanning beds. Skin cancer is the most common type of cancer worldwide, and its incidence continues to rise.
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in...
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in...
01:30Regulation of Food Intake
Short-term regulation of food intake primarily involves neural signals from the gastrointestinal (GI) tract, blood nutrient levels, and GI tract hormones. Communication between the gut and brain via vagal nerve fibers plays a significant role in evaluating the contents of the gut. Clinical studies have shown that protein ingestion produces a more prolonged response in these nerve fibers compared to an equivalent amount of glucose. Additionally, the activation of stretch receptors caused by GI...
01:19Cushing Syndrome II: Pathophysiology
Cortisol production is normally governed by the hypothalamic–pituitary–adrenal (HPA) axis, which maintains hormonal balance through tightly regulated feedback mechanisms. Disruption of this regulatory system is central to the development of Cushing syndrome, whether the excess cortisol originates from external medications or internal pathology. Persistent cortisol elevation alters metabolism, immune function, and endocrine signaling, producing the characteristic clinical features of the...