Question: What is (are) Laron syndrome ?
Answer: Laron syndrome is a condition that occurs when the body is unable to utilize growth hormone. It is primarily characterized by short stature. Other signs and symptoms vary but may include reduced muscle strength and endurance; hypoglycemia in infancy; delayed puberty; short limbs (arms and legs); and obesity. It is often caused by changes (mutations) in the GHR gene and is inherited in an autosomal recessive manner. Treatment is focused on improving growth and generally includes injections of insulin-like growth factor 1 (IGF-1).
Source: GARD

Question: What are the symptoms of Laron syndrome ?
Answer: What are the signs and symptoms of Laron syndrome? Laron syndrome is a rare condition in which the body is unable to use growth hormone. The primary symptom is short stature. Although affected people are generally close to average size at birth, they experience slow growth from early childhood. If left untreated, adult males with Laron syndrome typically reach a maximum height of about 4.5 feet and adult females may be just over 4 feet tall. Other signs and symptoms associated with the condition vary but may include: Reduced muscle strength and endurance Hypoglycemia in infancy Delayed puberty Small genitals Thin, fragile hair Dental abnormalities Short limbs (arms and legs) Obesity Distinctive facial features (protruding forehead, a sunken bridge of the nose, and blue sclerae) People affected by Laron syndrome appear to have a reduced risk of cancer and type 2 diabetes. The Human Phenotype Ontology provides the following list of signs and symptoms for Laron syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Abnormal facial shape 90% Aplasia/Hypoplasia involving the nose 90% Delayed eruption of teeth 90% Delayed skeletal maturation 90% High forehead 90% Microdontia 90% Reduced number of teeth 90% Truncal obesity 90% Abnormality of the elbow 50% Brachydactyly syndrome 50% Hypoglycemia 50% Hypoplasia of penis 50% Short toe 50% Skeletal muscle atrophy 50% Underdeveloped supraorbital ridges 50% Abnormality of lipid metabolism 7.5% Abnormality of the voice 7.5% Blue sclerae 7.5% Cognitive impairment 7.5% Depressed nasal ridge 7.5% Hypertrichosis 7.5% Hypohidrosis 7.5% Osteoarthritis 7.5% Prematurely aged appearance 7.5% Abnormal joint morphology - Abnormality of metabolism/homeostasis - Autosomal recessive inheritance - Delayed menarche - High pitched voice - Severe short stature - Short long bone - Small face - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD

Question: What causes Laron syndrome ?
Answer: What causes Laron syndrome? Laron syndrome is caused by changes (mutations) in the GHR gene. This gene encodes growth hormone receptor, which is a protein found on the outer membrane of cells throughout the body. Growth hormone receptor is designed to recognize and bind growth hormone, which triggers cellular growth and division. When growth hormone is bound to the growth hormone receptors on liver cells, specifically, insulin-like growth factor I (another important growth-promoting hormone) is produced. Mutations in GHR impair the function of growth hormone receptors which interferes with their ability to bind growth hormone. This disrupts normal growth and development of cells and prevents the production of insulin-like growth factor I which causes the many signs and symptoms of Laron syndrome.
Source: GARD

Question: Is Laron syndrome inherited ?
Answer: Is Laron syndrome inherited? Most cases of Laron syndrome are inherited in an autosomal recessive manner. This means that to be affected, a person must have a mutation in both copies of the responsible gene in each cell. The parents of an affected person usually each carry one mutated copy of the gene and are referred to as carriers. Carriers typically do not show signs or symptoms of the condition. When two carriers of an autosomal recessive condition have children, each child has a 25% (1 in 4) risk to have the condition, a 50% (1 in 2) risk to be a carrier like each of the parents, and a 25% chance to not have the condition and not be a carrier. Reports exist of rare families in which Laron syndrome appears to be inherited in an autosomal dominant manner. In these cases, a person only needs a change (mutation) in one copy of the responsible gene in each cell. In some cases, an affected person inherits the mutation from an affected parent. Other cases may result from new (de novo) mutations in the gene. These cases occur in people with no history of the disorder in their family. An affected person has a 50% chance with each pregnancy of passing along the altered gene to his or her child.
Source: GARD

Question: How to diagnose Laron syndrome ?
Answer: How is Laron syndrome diagnosed? A diagnosis of Laron syndrome is often suspected based on the presence of characteristic signs and symptoms. Additional testing can then be ordered to confirm the diagnosis and rule out other conditions that cause similar features. This generally includes blood tests to measure the levels of certain hormones that are often abnormal in people with Laron syndrome. For example, affected people may have elevated levels of growth hormone and reduced levels of insulin-like growth factor I. Genetic testing for changes (mutations) in the GHR gene can also be used to confirm a diagnosis in some cases.
Source: GARD

Question: What are the treatments for Laron syndrome ?
Answer: How might Laron syndrome be treated? There is currently no cure for Laron syndrome. Treatment is primarily focused on improving growth. The only specific treatment available for this condition is subcutaneous injections of insulin-like growth factor 1 (a growth-promoting hormone), often called IGF-1. IGF-1 stimulates linear growth (height) and also improves brain growth and metabolic abnormalities caused by long-term IGF-1 deficiency. It has also been shown to raise blood glucose levels, reduce cholesterol, and increase muscle growth. IGF-1 and GH levels should be closely monitored in people undergoing this treatment because overdosage of IGF-I causes a variety of health problems.
Source: GARD