Table 1.

The most common gene mutations related to monogenic obesity and their characteristic features (besides of severe obesity of early origin).

Gene Name	Disorders Causing the Development of Obesity
Melanocortin 4 receptor	Somatomegaly, increased head circumference, hyperinsulinemia
Leptin	Hypogonadotropic hypogonadism, hypothyroidism, growth hormone deficiency, immune deficiency
Leptin receptor	Hypogonadotropic hypogonadism, hypothyroidism, growth hormone deficiency, immune deficiency
Single-minded homolog 1	Autism, behavioral problems
Kinase suppressor of Ras 2	Insulin resistance, low heart rate, reduced basal metabolic rate
Proopiomelanocortin	ACTH/adrenal insufficiency, abnormal pigmentation
Protein convertase subtilisin/kexin 1	Neonatal diarrhea, hypoglycemia, hypothyroidism, adrenal insufficiency, diabetes insipidus
Neurotrophic receptor tyrosine kinase 2	Developmental delay, hyperactivity
Melanocortin 2 receptor accessory protein 2	None
SH2B adapter protein 1	Severe insulin resistance, behavioral difficulties, and developmental delay
Brain-derived neurotrophic factor	Developmental delay, hyperactivity