Obesitas door melanocortine-4-receptormutaties

Conflict of interest: none declared. Financial support: none declared.

• Obesity is usually the result of a combination of genetic and lifestyle factors.

• In monogenic obesity, overweight is caused by a single gene mutation.

• The most frequent form of monogenic obesity is caused by mutations in the gene that codes for the melanocortin-4 receptor (MC4R gene).

• Approximately 2% of Dutch children with obesity have a mutation in the MC4R gene.

• Children with homozygous and ‘compound’ heterozygous MC4R mutations have a phenotype distinguished by extreme overweight at an early age and hyperphagia.

• Children with heterozygous MC4R mutations have a more subtle phenotype and are difficult to distinguish clinically from obese children without this mutation.

• MC4R mutations can be identified by DNA diagnostics.

• Drug treatment is not yet available for this condition.