Laron syndrome is an autosomal recessive congenital disorder distinguished by marked short stature correlated with normal or high serum growth hormone (GH) and low serum insulin-like growth factor-1 (IGF-1) levels which fail to increase following exogenous GH administration. The disorder affects both males and females equally, with a prevalence of 1-9/1,000,000, and is more frequent in Semitic or Mediterranean populations. Worldwide, over 250 cases have been portrayed.
Patients generally retain normal intrauterine growth and birth size, however, postnatal growth is decelerated and usually disproportional with delayed bone age; adult stature ranges between -3 to -12 SD. Motor development is belated due to diminished muscle mass and newborns are often portrayed with hypoglycemia and a micropenis. Puberty is often belated, with frequent facial dysmorphism, which consists of protruding, high forehead, shallow orbits, hypoplastic nasal bridge, and small chin. Throughout infancy, sparse hair can be observed with relative obesity, delayed tooth eruption, high-pitched voice, thin bones and skin, and decreased sweating. Moreover, patients might seldom suffer from blue sclera and hip degeneration. Females suffering from Laron syndrome possess normal reproductive capability but require Cesarean delivery.
Larson syndrome is diagnosed through clinical and biological findings including the results of hormonal tests that can disclose either normal or elevated levels of GH and low IGF-1 levels, which fail to increase following exogenous GH administration. Meanwhile, for an accurate etiological diagnosis, genetic tests are employed. The differential diagnosis ought to include severe growth hormone deficiency (GHD) and growth delay as a result of IGF-I resistance, with secondary IGF-I deficiency typically as a result of nutritional difficulties or chronic pediatric diseases.
Genetic counseling can be offered to parents of an affected person prior to further pregnancy, to inform them of the risks and the accessible diagnostic techniques. Laron syndrome can be managed through treatment with daily subcutaneous injections of mecasermin, recombinant human IGF-I, and diet with sufficient caloric intake to improve patients' growth. The disease cannot be treated fully or prevented however, frequent feeding is essential to prevent hypoglycemia. Prognosis appears to be of high-quality although with age, subjects can develop obesity, hypercholesterolemia and suffer from a higher risk of fractures as a result of osteopenia.