Age of obesity onset in MC4R mutation carriers.

OBJECTIVES: The mutations in gene for the melanocortin-4 receptor (MC4R) are the most common etiology factors of monogenic obesity development. Recently, it has been shown that current life style has a significant impact on the phenotype of MC4R mutation carriers - increases the penetrance of the mutations. We aimed to study the impact of the current age on the time of obesity onset among MC4R mutation carriers. METHODS: DNA analysis of the MC4R gene was performed in 268 unrelated Slovak and Moravian obese children and adolescents 18 years and 28 blood relatives >18 years of the probands with a mutation. RESULTS: Three different previously described heterozygous loss of function MC4R mutations (p.Ser19Alafs*34, p.Ser127Leu, and p.Gly181Asp) were found in 3 <18 years probands, 3 adult probands, and 6 adult obese/overweight family relatives. The age of obesity onset in mutation carriers was 1 year in all probands in the children group and 1-35 years (median 11 years) in adults. The age of the obesity onset significantly correlated (R=0.809, p=0.028) with the current age in all of the MC4R mutation carriers. CONCLUSIONS: The age of obesity onset in the present child generation of MC4R mutation carriers is decreasing compared to the age of onset in their parents' generation. This is in agreement with similarly increasing penetrance of obesity in MC4R mutation carriers and it points out to escalation of obesogenic potential of environment.

Molecular-genetic aspects of familial hypercholesterolemia.

Familial hypercholesterolemia (FH) is the world's most abundant and the most common heritable disorder of lipid metabolism. The prevalence of the disease in general population is 1:500. Therefore the approximate number of FH patients all over the world is 14 million. From the genetic point of view the disease originates as a result of mutations in genes affecting the processing of LDL particles from circulation, resulting in an increase in LDL cholesterol and hence total cholesterol. These are mutations in genes encoding LDL receptor, apolipoprotein B, proprotein convertase subtilisin/kexin 9 and LDL receptor adaptor protein 1. Cholesterol depositing in tissues and blood vessels of individuals creates tendon xanthoma, xanthelesma and arcus lipoides cornae. Due to the increased deposition of cholesterol in blood vessels, atherosclerosis process is accelerated, what leads to a significantly higher risk of premature cardiovascular diseases. Therefore, early clinical diagnosis confirmed by the DNA analysis, and effective treatment are crucial to reduce the mortality and high risk of premature atherosclerotic complications.